Powell, J W; Schneider, D A. Tectonics vol. 41, issue 9, 2022 p. 1-22, https://doi.org/10.1029/2021TC007065
<a href="https://geoscan.nrcan.gc.ca/images/geoscan/20220095.jpg"><img src="https://geoscan.nrcan.gc.ca/images/geoscan/20220095.jpg" title="Tectonics vol. 41, issue 9, 2022 p. 1-22, https://doi.org/10.1029/2021TC007065" height="150" border="1" /></a>

Spalding, J; Powell, J W; Schneider, D A; Fallas, K M. Marine and Petroleum Geology 155, 106358, 2023 p. 1-18, https://doi.org/10.1016/j.marpetgeo.2023.106358
<a href="https://geoscan.nrcan.gc.ca/images/geoscan/20230078.jpg"><img src="https://geoscan.nrcan.gc.ca/images/geoscan/20230078.jpg" title="Marine and Petroleum Geology 155, 106358, 2023 p. 1-18, https://doi.org/10.1016/j.marpetgeo.2023.106358" height="150" border="1" /></a>

Between now and Christmas, Dn. Michael Hyatt teaches a short series entitled Peace on Earth. In this episode he focuses in on unresolved conflict at home, work, and church and the tools given to us by God to avoid them.

The electric field responses of the average and local lattice strains and polar nanoregions of relaxor ferroelectric PMN-30PT single crystals were revealed by multi-scale and time-resolved X-ray diffraction under DC and AC electric fields.

The position- and time-resolved monitoring of a mechanochemical reaction using synchrotron powder X-ray diffraction revealed a position-independent increase rate of product in the jar of a shaker mill.

We investigated the position and time dependence of a mechanochemical reaction induced by ball milling using in situ synchrotron powder X-ray diffraction with changing X-ray irradiation position. The mechanochemical reduction of AgCl with Cu was monitored in situ with the X-rays incident at two different vertical positions on the jar. Our previously developed multi-distance Rietveld method was applied to analyze the in situ diffraction data with a 1 min resolution. Both the vertical and the horizontal sample positions were determined using the sample-to-detector distances from the in situ data. Position dependence was found in the powder spreading and induction time. We reveal that the increase rate of the product is independent of the sample position when measured with a 1 min time resolution, confirming the validity of in situ monitoring of part of the space in a milling jar for a gradual mechanochemical reaction.

Lead-based relaxor ferroelectrics exhibit giant piezoelectric properties owing to their heterogeneous structures. The average and local structures measured by single-crystal X-ray diffraction under DC and AC electric fields are reviewed in this article. The position-dependent local lattice strain and the distribution of polar nanodomains and nanoregions show strong electric field dependence, which contributes to the giant piezoelectric properties.

The X-ray emission spectrometer at SPring-8 BL07LSU has recently been upgraded with advanced modifications that enable the rotation of the spectrometer with respect to the scattering angle. This major upgrade allows the scattering angle to be flexibly changed within the range of 45–135°, which considerably simplifies the measurement of angle-resolved X-ray emission spectroscopy. To accomplish the rotation system, a sophisticated sample chamber and a highly precise spectrometer rotation mechanism have been developed. The sample chamber has a specially designed combination of three rotary stages that can smoothly move the connection flange along the wide scattering angle without breaking the vacuum. In addition, the spectrometer is rotated by sliding on a flat metal surface, ensuring exceptionally high accuracy in rotation and eliminating the need for any further adjustments during rotation. A control system that integrates the sample chamber and rotation mechanism to automate the measurement of angle-resolved X-ray emission spectroscopy has also been developed. This automation substantially streamlines the process of measuring angle-resolved spectra, making it far easier than ever before. Furthermore, the upgraded X-ray emission spectrometer can now also be utilized in diffraction experiments, providing even greater versatility to our research capabilities.

The advent of diffraction-limited storage rings (DLSRs) has boosted the brilliance or coherent flux by one to two orders of magnitude with respect to the previous generation. One consequence of this brilliance enhancement is an increase in the flux density or number of photons per unit of area and time, which opens new possibilities for the spatiotemporal resolution of X-ray imaging techniques. This paper studies the time-resolved microscopy capabilities of such facilities by benchmarking the ForMAX beamline at the MAX IV storage ring. It is demonstrated that this enhanced flux density using a single harmonic of the source allows micrometre-resolution time-resolved imaging at 2000 tomograms per second and 1.1 MHz 2D acquisition rates using the full dynamic range of the detector system.

The split-and-delay unit (SDU) at FLASH2 will be upgraded to enable the simultaneous operation of two temporally, spatially and spectrally separated probe beams when the free-electron laser undulators are operated in a two-color scheme. By means of suitable thin filters and an optical grating beam path a wide range of combinations of photon energies in the spectral range from 150 eV to 780 eV can be chosen. In this paper, simulations of the spectral transmission and performance parameters of the filter technique are discussed, along with a monochromator with dispersion compensation presently under construction.

The technique of time-resolved macromolecular crystallography (TR-MX) has recently been rejuvenated at synchrotrons, resulting in the design of dedicated beamlines. Using pump–probe schemes, this should make the mechanistic study of photoactive proteins and other suitable systems possible with time resolutions down to microseconds. In order to identify relevant time delays, time-resolved spectroscopic experiments directly performed on protein crystals are often desirable. To this end, an instrument has been built at the icOS Lab (in crystallo Optical Spectroscopy Laboratory) at the European Synchrotron Radiation Facility using reflective focusing objectives with a tuneable nanosecond laser as a pump and a microsecond xenon flash lamp as a probe, called the TR-icOS (time-resolved icOS) setup. Using this instrument, pump–probe spectra can rapidly be recorded from single crystals with time delays ranging from a few microseconds to seconds and beyond. This can be repeated at various laser pulse energies to track the potential presence of artefacts arising from two-photon absorption, which amounts to a power titration of a photoreaction. This approach has been applied to monitor the rise and decay of the M state in the photocycle of crystallized bacteriorhodopsin and showed that the photocycle is increasingly altered with laser pulses of peak fluence greater than 100 mJ cm−2, providing experimental laser and delay parameters for a successful TR-MX experiment.

Over the last decade, the development of time-resolved serial crystallography (TR-SX) at X-ray free-electron lasers (XFELs) and synchrotrons has allowed researchers to study phenomena occurring in proteins on the femtosecond-to-minute timescale, taking advantage of many technical and methodological breakthroughs. Protein crystals of various sizes are presented to the X-ray beam in either a static or a moving medium. Photoactive proteins were naturally the initial systems to be studied in TR-SX experiments using pump–probe schemes, where the pump is a pulse of visible light. Other reaction initiations through small-molecule diffusion are gaining momentum. Here, selected examples of XFEL and synchrotron time-resolved crystallography studies will be used to highlight the specificities of the various instruments and methods with respect to time resolution, and are compared with cryo-trapping studies.

Molecular structures can be determined in vitro and in situ with cryo-electron microscopy (cryo-EM). Specimen preparation is a major obstacle in cryo-EM. Typical sample preparation is orders of magnitude slower than biological processes. Time-resolved cryo-EM (TR-cryo-EM) can capture short-lived states. Here, Cryo-EM sample preparation with light-activated molecules (C-SPAM) is presented, an open-source, photochemistry-coupled device for TR-cryo-EM that enables millisecond resolution and tunable timescales across broad biological applications.

Serial crystallography requires large numbers of microcrystals and robust strategies to rapidly apply substrates to initiate reactions in time-resolved studies. Here, we report the use of droplet miniaturization for the controlled production of uniform crystals, providing an avenue for controlled substrate addition and synchronous reaction initiation. The approach was evaluated using two enzymatic systems, yielding 3 µm crystals of lysozyme and 2 µm crystals of Pdx1, an Arabidopsis enzyme involved in vitamin B6 biosynthesis. A seeding strategy was used to overcome the improbability of Pdx1 nucleation occurring with diminishing droplet volumes. Convection within droplets was exploited for rapid crystal mixing with ligands. Mixing times of <2 ms were achieved. Droplet microfluidics for crystal size engineering and rapid micromixing can be utilized to advance time-resolved serial crystallography.

Here, a machine-learning method based on a kinetically informed neural network (NN) is introduced. The proposed method is designed to analyze a time series of difference electron-density maps from a time-resolved X-ray crystallographic experiment. The method is named KINNTREX (kinetics-informed NN for time-resolved X-ray crystallography). To validate KINNTREX, multiple realistic scenarios were simulated with increasing levels of complexity. For the simulations, time-resolved X-ray data were generated that mimic data collected from the photocycle of the photoactive yellow protein. KINNTREX only requires the number of intermediates and approximate relaxation times (both obtained from a singular valued decomposition) and does not require an assumption of a candidate mechanism. It successfully predicts a consistent chemical kinetic mechanism, together with difference electron-density maps of the intermediates that appear during the reaction. These features make KINNTREX attractive for tackling a wide range of biomolecular questions. In addition, the versatility of KINNTREX can inspire more NN-based applications to time-resolved data from biological macromolecules obtained by other methods.

Light–oxygen–voltage (LOV) domains are small photosensory flavoprotein modules that allow the conversion of external stimuli (sunlight) into intra­cellular signals responsible for various cell behaviors (e.g. phototropism and chloro­plast relocation). This ability relies on the light-induced formation of a covalent thio­ether adduct between a flavin chromophore and a reactive cysteine from the protein environment, which triggers a cascade of structural changes that result in the activation of a serine/threonine (Ser/Thr) kinase. Recent developments in time-resolved crystallography may allow the activation cascade of the LOV domain to be observed in real time, which has been elusive. In this study, we report a robust protocol for the production and stable delivery of microcrystals of the LOV domain of phototropin Phot-1 from Chlamydomonas reinhardtii (CrPhotLOV1) with a high-viscosity injector for time-resolved serial synchrotron crystallography (TR-SSX). The detailed process covers all aspects, from sample optimization to data collection, which may serve as a guide for soluble protein preparation for TR-SSX. In addition, we show that the crystals obtained preserve the photoreactivity using infrared spectroscopy. Furthermore, the results of the TR-SSX experiment provide high-resolution insights into structural alterations of CrPhotLOV1 from Δt = 2.5 ms up to Δt = 95 ms post-photoactivation, including resolving the geometry of the thio­ether adduct and the C-terminal region implicated in the signal transduction process.

Time-resolved high-energy X-ray diffraction was used during growth of ultrathin NixFe3−xO4 films with varying Ni content (0 ≤ x ≤ 1.5) deposited on MgO(001) substrates by reactive molecular beam epitaxy, providing an insight into the growth dynamics of these films. In order to obtain structural information, reciprocal-space maps were recorded and the temporal evolution of the Bragg peaks specific to the octahedral and tetrahedral lattice sites of the inverse spinel structure of NixFe3−xO4 was observed during growth of the films. A time delay, corresponding to a coverage of 1.2–1.8 nm, between the appearance of the Bragg reflections originating from octahedral sites and reflections originating exclusively from tetrahedral sites indicates that the ferrite films grow in two stages. In the initial growth phase, a rock salt interface layer is formed. Afterwards, a structural transition occurs and the films grow in an inverse spinel structure. The thickness of the initial rock salt phase was found to increase with Ni content and to be responsible for atypical strain in the thin films. Films with Ni contents x > 1 do not show a structural transition. These films remain in a (deficient) rock salt structure consisting of a mixed Ni–Fe oxide and do not form a spinel structure at all. They show an increased number of NiO clusters as detected by X-ray photoelectron spectroscopy of the valence band, accompanied by a significant roughening of the films.

An anomalous ultra-small-angle X-ray scattering (AUSAXS) system has been constructed at BL28XU at SPring-8 for time-resolved AUSAXS experiments. The path length was extended to 9.1 m and a minimum of q = 0.0069 nm−1 was attained. Scattering profiles at 0.0069 to 0.3 nm−1 were successfully obtained at 17 different X-ray energies in 30 s using the BL28XU optical setup, which enables adjustment of the energy of the incident X-rays quickly without the beam position drifting. Time-resolved measurements were conducted to investigate changes in the structure of zinc compounds in poly(styrene-ran-butadiene) rubber during vulcanization. A change in energy dependence of the scattered intensity with time was found during vulcanization, suggesting the transformation of zinc in the reaction.

With the emergence of ultrafast X-ray sources, interest in following fast processes in small molecules and macromolecules has increased. Most of the current research into ultrafast structural dynamics of macromolecules uses X-ray free-electron lasers. In parallel, small-scale laboratory-based laser-driven ultrafast X-ray sources are emerging. Continuous development of these sources is underway, and as a result many exciting applications are being reported. However, because of their low flux, such sources are not commonly used to study the structural dynamics of macromolecules. This article examines the feasibility of time-resolved powder diffraction of macromolecular microcrystals using a laboratory-scale laser-driven ultrafast X-ray source.

Evidence exists that people who lived or worked at Camp Lejeune Marine Base in North Carolina between the 1950s and 1985 were exposed to the industrial solvents tricholorethylene (TCE) or perchloroethylene (PCE) in their water supply, but strong scientific evidence is not available to determine whether health problems among those exposed are due to the contaminants, says a new report from the National Research Council.

Decrypting the molecular basis of cellular drug phenotypes by dose-resolved expression proteomics  Nature.com

Resolutions are easy to make, even easier to break. But what if a story or idea can motivate us in a whole new way? This hour, TED speakers offer different perspectives on our most common resolutions. Guests include neuroscientists Wendy Suzuki and Sandra Aamodt, science journalist Catherine Price, behavioral scientist Wendy De La Rosa, and authors Pico Iyer and A.J. Jacobs.

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Original Broadcast Date: January 13, 2023. Resolutions are easy to make, even easier to break. But what if a story or idea can motivate us in a whole new way? This hour, TED speakers offer different perspectives on our most common resolutions. Guests include neuroscientists Wendy Suzuki and Sandra Aamodt, science journalist Catherine Price, behavioral scientist Wendy De La Rosa, and authors Pico Iyer and A.J. Jacobs.

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Our server move to Cloudways is complete, but it hasn’t been entirely smooth. Various security-related changes at Cloudways caused access errors that proved difficult to troubleshoot.

1. Corporate regulator sues Cbus over unresolved insurance claims  Sydney Morning Herald
2. VIDEO Cbus taken to court accused of failing to pay thousands of claims  ABC News
3. Super fund in strife over $20m in delayed payments  The Canberra Times

In a classic bit from an early Seinfeld, Jerry and Elaine are at the airport, trying to pick up the rental car that Jerry had reserved. As usual, things go poorly and get awkward fast:

Seinfeld - "Reservations"

JERRY: I don't understand...I made a reservation. Do you have my reservation?
AGENT: Yes, we do. Unfortunately, we ran out of cars.
JERRY: But, the reservation keeps the car here. That's why you have the reservation.
AGENT: I know why we have reservations.
JERRY: I don't think you do. If you did, I'd have a car. See, you know how to take the reservation--you just don't know how to hold the reservation. And, that's really the most important part of the reservation...the holding. Anybody can just TAKE them. [grabs chaotically at air]

And, how weirdly similar is that to our conflicted relationship with New Year's resolutions?

In Seinfeldspeak?

See, you know how to make the resolution, you just don't know how to keep the resolution. And, that's really the most important part of the resolution...the keeping. Anybody can just MAKE them!

Oversimplified? Probably.

But, ask yourself. Why this? And, why now? Or, why again?

Welcome to Resolvers Anonymous: I'm 'Merlin M.'

A few years ago, I shared a handful of stories on the failures that have led to my own cynicism about the usefulness of life-inverting resolutions. Because, yeah, I've historically been a big resolver.

Here's what I said when I first suggested favoring "Fresh Starts and Modest Changes" over reinventions:

Download MP3 of "Fresh Starts & Modest Changes"

Five years on, I think I probably feel even more strongly about this.

Partly because I've watched and read and heard the cyclical lamentations of folks who decided to use superficial totems (like new calendars) as an ad hoc coach and prime mover. And, partly because, in my capacity as a makebelieve productivity expert, I continue to see how self-defeating it is to pretend that past can ever be less than prologue--that we can each ignore yesterday's weather if we really wish hard enough for a sun-drenched day at the beach.

It simply doesn't work.

Companies that think they'll be Google for buying bagels. Writers who think they'll get published if they order a new pen. Obese people who think they'll become marathon runners if they pick up some new running shoes. And, regular old people with good hearts who continue to confuse new lives with new clothes.

Has this worked before? Can you look back on a proud legacy of successful New Year's resolutions that would suggest you're making serious progress by repeatedly making a list about fundamental life changes while slamming prosecco and wearing a pointy paper hat?

My bet is that most people who are seeing the kind of change and growth and improvement that sticks tend to avoid these sorts of dramatic, geometric attempts to leap blindly toward the mountain of perfection.

I'll go further and say that the repeated compulsion to resolve and resolve and resolve is actually a terrific marker that you're not really ready to change anything in a grownup and sustainable way. You probably just want another magic wand.

Otherwise you'd already be doing the things you've resolved to do. You'd already be living those changes. And, you'd already be seeing actual improvements rather than repeatedly making lists of all the ways you hope your annual hajj to the self-improvement genie will fix you.

Then, of course, we make things way worse by blaming everything on our pancakes.

Regarding "The First Pancake Problem"

Anyone who's ever made America's favorite round and flat breakfast food is familiar with the phenomenon of The First Pancake.

No matter how good a cook you are, and no matter how hard you try, the first pancake of the batch always sucks.

It comes out burnt or undercooked or weirdly shaped or just oddly inedible and aesthetically displeasing. Just ask your kids.

At least compared to your normal pancake--and definitely compared to the far superior second and subsequent pancakes that make the cut and get promoted to the pile destined for the breakfast table--the first one's always a disaster.

I'll leave it to the physicists and foodies in the gallery to develop a unified field theory on exactly why our pancake problem crops up with such unerring dependability. But I will share an orthogonal theory: you will be a way happier and more successful cook if you just accept that your first pancake is and always will be a universally flukey mess.

But, that shouldn't mean you never make another pancake.

So Loud. Then, So Quiet.

I offer all of this because today is January 7th, gang. And, for the past week, all over the web, legions of well-intentioned and seemingly strong-willed humans have been declaring their resolved intention to make this a year of more and better metaphorical pancakes.

And, like clockwork--usually around today or maybe tomorrow--a huge cohort of those cooks will begin to abandon their resolve and go back to thinking all their pancakes have to suck. Just because that first one failed.

And, as is the case every year, online and off, there won't be nearly as many breathless updates to properly bookend how poorly our annual ritual of aspirational change has fared. Which is instructive.

Not because new year's resolutions are a universally bad idea. And, not because Change is Bad. And, not because we should be embarrassed about occasionally falling short of our own (frequently unreasonable) aspirations.

I suspect we tout the resolution, but whisper the failure because we blame the cook. Or, worse, fingers point toward the pancake. Instead of just admitting that the resolution itself was simply unrealistic or fundamentally foreign.

And, that's a shame.

Remember, there's no "I" in "unreasonable"

Granted, I'm merely re-repeating a point I've struggled to make (to both others and myself) for years now. But, it will bear repeating every January in perpetuity.

Resist the urge to pin the fate of things you really care about to anything that's not truly yourself. The "yourself" who has a real life with complicated demands. The "yourself" who's going to face a hard slog trying to fold a new life out of a fresh calendar.

Calendars are just paper and staples. They can't make you care. And they can't help you spin around like Diana Prince, and instantly turn into Wonder Woman. Especially, if you're not already a hot and magical Amazon princess.

First, be reasonable. Don't set yourself up for failure by demanding things that you've never come close to achieving before. I realize this is antithetical to most self-improvement bullshit, but that's exactly the point. If you were already a viking, you wouldn't need to build a big boat. Start with where you are right now. Not with where you wish you'd been.

Also, accept that the first pancake will always suck. Hell, if you've never picked up a spatula before, be cool with the fact that your first hundred pancakes might suck. This is, as I've said, huge. Failure is the sound of beginning to suck a little less.

And, finally, also be clear about the sanity of the motivations underlying your expectations--step back to observe what's truly broken, derive a picture of incremental success that seems do-able, and really resolve to do whatever you can realistically do to actually get better. Rather than "something something I suddenly become all different."

At this point, you have logistical options for both execution and troubleshooting:

• Make a modest plan that you can envision actually doing without upending your real life;
• Build more sturdy scaffolding for sticking with whatever plan you've chosen;
• Make a practice of learning to not mind the duds--including those messed-up first pancakes;
• Or--seriously?--just accept that you never really cared that much about making breakfast in the first place. Care is not optional.

Otherwise, really, you'd never need to resolve to do anything. You'd already just be cooking a lot. Instead of being all mad and depressed about not cooking.

But, please. All I really ask of you. Don't blame the pancake. It's not really the pancake's fault.

Like me, the pancake just wants you to be happy. This and every other new year.

Yi Zhang
Sep 1, 2005; 4:1240-1250
Research

Matthias Schittmayer
Dec 1, 2020; 19:2104-2114
Research

Despite the crucial function of the small intestine in nutrient uptake our understanding of the molecular events underlying the digestive function is still rudimentary. Recent studies demonstrated that enterocytes do not direct the entire dietary triacylglycerol toward immediate chylomicron synthesis. Especially after high-fat challenges, parts of the resynthesized triacylglycerol are packaged into cytosolic lipid droplets for transient storage in the endothelial layer of the small intestine. The reason for this temporary storage of triacylglycerol is not completely understood. To utilize lipids from cytosolic lipid droplets for chylomicron synthesis in the endoplasmic reticulum, stored triacylglycerol has to be hydrolyzed either by cytosolic lipolysis or lipophagy. Interestingly, triacylglycerol storage and chylomicron secretion rates are unevenly distributed along the small intestine, with the proximal jejunum exhibiting the highest intermittent storage capacity. We hypothesize that correlating hydrolytic enzyme activities with the reported distribution of triacylglycerol storage and chylomicron secretion in different sections of the small intestine is a promising strategy to determine key enzymes in triacylglycerol remobilization. We employed a serine hydrolase specific activity-based labeling approach in combination with quantitative proteomics to identify and rank hydrolases based on their relative activity in 11 sections of the small intestine. Moreover, we identified several clusters of enzymes showing similar activity distribution along the small intestine. Merging our activity-based results with substrate specificity and subcellular localization known from previous studies, carboxylesterase 2e and arylacetamide deacetylase emerge as promising candidates for triacylglycerol mobilization from cytosolic lipid droplets in enterocytes.

On December 3, a federal appeals court ruled against one of the FDA’s untouchable restrictions on industry—thou shalt not promote the off-label use of pharmaceutical products. An industry that is little interested in constitutional law suddenly finds itself talking about the First Amendment and whether, and on what grounds, the case will be appealed. Meantime, the court’s decision left FDA Matters torn between cheering and booing. Patients are poorly served if their doctor is prescribing drugs without being able to tap into all sources of relevant knowledge. However, permitting off-label promotion undercuts the incentive for companies to thoroughly investigate the safety and efficacy of a drug for a second or third use.

Fintech giant Square says its services are coming back online after a daylong outage left small business owners unable to process payments. The Block-owned company had, up until Friday morning on the U.S. West Coast, been battling a prolonged outage that had downed its services since Thursday afternoon. In a new posting on its status […]

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A new method based on time-resolved X-ray diffraction is proposed in order to measure the elastic strain and stress during ultrasonic fatigue loading experiments. Pure Cu was chosen as an example material for the experiments using a 20 kHz ultrasonic fatigue machine mounted on the six-circle diffractometer available at the DiffAbs beamline on the SOLEIL synchrotron facility in France. A two-dimensional hybrid pixel X-ray detector (XPAD3.2) was triggered by the strain gage signal in a synchronous data acquisition scheme (pump–probe-like). The method enables studying loading cycles with a period of 50 µs, achieving a temporal resolution of 1 µs. This allows a precise reconstruction of the diffraction patterns during the loading cycles. From the diffraction patterns, the position of the peaks, their shifts and their respective broadening can be deduced. The diffraction peak shift allows the elastic lattice strain to be estimated with a resolution of ∼10−5. Stress is calculated by the self-consistent scale-transition model through which the elastic response of the material is estimated. The amplitudes of the cyclic stresses range from 40 to 120 MPa and vary linearly with respect to the displacement applied by the ultrasonic machine. Moreover, the experimental results highlight an increase of the diffraction peak broadening with the number of applied cycles.

Serial synchrotron crystallography (SSX) is an emerging technique for static and time-resolved protein structure determination. Using specifically patterned silicon chips for sample delivery, the `hit-and-return' (HARE) protocol allows for efficient time-resolved data collection. The specific pattern of the crystal wells in the HARE chip provides direct access to many discrete time points. HARE chips allow for optical excitation as well as on-chip mixing for reaction initiation, making a large number of protein systems amenable to time-resolved studies. Loading of protein microcrystals onto the HARE chip is streamlined by a novel vacuum loading platform that allows fine-tuning of suction strength while maintaining a humid environment to prevent crystal dehydration. To enable the widespread use of time-resolved serial synchrotron crystallography (TR-SSX), detailed technical descriptions of a set of accessories that facilitate TR-SSX workflows are provided.

An expectation maximization algorithm is implemented to resolve the indexing ambiguity which arises when merging data from many crystals in protein crystallography, especially in cases where partial reflections are recorded in serial femtosecond crystallography (SFX) at XFELs.

Temperature is a ubiquitous environmental variable used to explore materials structure, properties and reactivity. This article reports a new paradigm for variable-temperature measurements that varies the temperature continuously across a sample such that temperature is measured as a function of sample position and not time. The gradient approach offers advantages over conventional variable-temperature studies, in which temperature is scanned during a series measurement, in that it improves the efficiency with which a series of temperatures can be probed and it allows the sample evolution at multiple temperatures to be measured in parallel to resolve kinetic and thermodynamic effects. Applied to treat samples at a continuum of temperatures prior to measurements at ambient temperature, the gradient approach enables parametric studies of recovered systems, eliminating temperature-dependent structural and chemical variations to simplify interpretation of the data. The implementation of spatially resolved variable-temperature measurements presented here is based on a gradient-heater design that uses a 3D-printed ceramic template to guide the variable pitch of the wire in a resistively heated wire-wound heater element. The configuration of the gradient heater was refined on the basis of thermal modelling. Applications of the gradient heater to quantify thermal-expansion behaviour, to map metastable polymorphs recovered to ambient temperature, and to monitor the time- and temperature-dependent phase evolution in a complex solid-state reaction are demonstrated.

Instrumentation for time-resolved small-angle neutron scattering measurements with sub-millisecond time resolution, based on Gähler's TISANE (time-involved small-angle neutron experiments) concept, is in operation at NIST's Center for Neutron Research. This implementation of the technique includes novel electronics for synchronizing the neutron pulses from high-speed counter-rotating choppers with a periodic stimulus applied to a sample. Instrumentation details are described along with measurements demonstrating the utility of the technique for elucidating the reorientation dynamics of anisometric magnetic particles.

The present work reports on the charge and spin density modelling of YTiO3 in its ferromagnetic state (TC = 27 K). Accurate polarized neutron diffraction and high-resolution X-ray diffraction (XRD) experiments were carried out on a single crystal at the ORPHÉE reactor (LLB) and SPRING8 synchrotron source. The experimental data are modelled by the spin resolved pseudo-atomic multipolar model (Deutsch et al., 2012). The refinement strategy is discussed and the result of this electron density modelling is compared with that from XRD measured at 100 K and with density functional theory calculations. The results show that the spin and charge densities around the Ti atom have lobes directed away from the O atoms, confirming the filling of the t2g orbitals of the Ti atom. The dxy orbital is less populated than dxz and dyz, which is a sign of a partial lift of degeneracy of the t2g orbitals. This study confirms the orbital ordering at low temperature (20 K), which is already present in the paramagnetic state above the ferromagnetic transition (100 K).

Structural biology generally provides static snapshots of protein conformations that can provide information on the functional mechanisms of biological systems. Time-resolved structural biology provides a means to visualize, at near-atomic resolution, the dynamic conformational changes that macromolecules undergo as they function. X-ray free-electron-laser technology has provided a powerful tool to study enzyme mechanisms at atomic resolution, typically in the femtosecond to picosecond timeframe. Complementary to this, recent advances in the resolution obtainable by electron microscopy and the broad range of samples that can be studied make it ideally suited to time-resolved approaches in the microsecond to millisecond timeframe to study large loop and domain motions in biomolecules. Here we describe a cryo-EM grid preparation device that permits rapid mixing, voltage-assisted spraying and vitrification of samples. It is shown that the device produces grids of sufficient ice quality to enable data collection from single grids that results in a sub-4 Å reconstruction. Rapid mixing can be achieved by blot-and-spray or mix-and-spray approaches with a delay of ∼10 ms, providing greater temporal resolution than previously reported mix-and-spray approaches.

The optical design of a Hettrick–Underwood-style soft X-ray spectrometer with Wolter type 1 mirrors is presented. The spectrometer with a nominal length of 3.1 m can achieve a high resolving power (resolving power higher than 10000) in the soft X-ray regime when a small source beam (<3 µm in the grating dispersion direction) and small pixel detector (5 µm effective pixel size) are used. Adding Wolter mirrors to the spectrometer before its dispersive elements can realize the spatial imaging capability, which finds applications in the spectroscopic studies of spatially dependent electronic structures in tandem catalysts, heterostructures, etc. In the pump–probe experiments where the pump beam perturbs the materials followed by the time-delayed probe beam to reveal the transient evolution of electronic structures, the imaging capability of the Wolter mirrors can offer the pixel-equivalent femtosecond time delay between the pump and probe beams when their wavefronts are not collinear. In combination with some special sample handing systems, such as liquid jets and droplets, the imaging capability can also be used to study the time-dependent electronic structure of chemical transformation spanning multiple time domains from microseconds to nanoseconds. The proposed Wolter mirrors can also be adopted to the existing soft X-ray spectrometers that use the Hettrick–Underwood optical scheme, expanding their capabilities in materials research.

Elucidating the structural dynamics of small molecules and proteins in the liquid solution phase is essential to ensure a fundamental understanding of their reaction mechanisms. In this regard, time-resolved X-ray solution scattering (TRXSS), also known as time-resolved X-ray liquidography (TRXL), has been established as a powerful technique for obtaining the structural information of reaction intermediates and products in the liquid solution phase and is expected to be applied to a wider range of molecules in the future. A TRXL experiment is generally performed at the beamline of a synchrotron or an X-ray free-electron laser (XFEL) to provide intense and short X-ray pulses. Considering the limited opportunities to use these facilities, it is necessary to verify the plausibility of a target experiment prior to the actual experiment. For this purpose, a program has been developed, referred to as S-cube, which is short for a Solution Scattering Simulator. This code allows the routine estimation of the shape and signal-to-noise ratio (SNR) of TRXL data from known experimental parameters. Specifically, S-cube calculates the difference scattering curve and the associated quantum noise on the basis of the molecular structure of the target reactant and product, the target solvent, the energy of the pump laser pulse and the specifications of the beamline to be used. Employing a simplified form for the pair-distribution function required to calculate the solute–solvent cross term greatly increases the calculation speed as compared with a typical TRXL data analysis. Demonstrative applications of S-cube are presented, including the estimation of the expected TRXL data and SNR level for the future LCLS-II HE beamlines.

A new approach to variable-temperature measurements is presented, where the sample temperature changes continuously as a function of position.

Instrumentation for sub-millisecond time-resolved small-angle neutron scattering measurements at NIST is described and applied to the reorientation dynamics of elongated hematite nanoparticles.

Evidence exists that people who lived or worked at Camp Lejeune Marine Base in North Carolina between the 1950s and 1985 were exposed to the industrial solvents tricholorethylene (TCE) or perchloroethylene (PCE) in their water supply, but strong scientific evidence is not available to determine whether health problems among those exposed are due to the contaminants, says a new report from the National Research Council.

A new concept takes the discussion out of the courtroom, where the battle has been fought for 20 years.