Search

AbstractBackground Previous reports have not reached consistent results regarding the prognostic significance of the controlling nutritional status (CONUT) score in biliary tract cancer (BTC). Therefore, the present meta-analysis was conducted to investigate the precise role of the CONUT score in predicting the prognosis of BTC.Methods Electronic platforms including Web of Science, PubMed, Cochrane Library, and Embase were comprehensively searched up to May 2, 2023. We also determined combined hazard ratios (HRs) and 95% confidence intervals (CIs) to estimate the role of the CONUT score in predicting the prognosis of patients with BTC.Results Ten studies involving 1,441 patients were included in the present study. Nine studies treated patients with surgical resection, and one study used percutaneous transhepatic biliary stenting (PTBS) plus 125I seed intracavitary irradiation. Based on the combined data, a higher CONUT score significantly predicted dismal overall survival (OS) (HR = 1.94, 95%CI = 1.41–2.66, p

Active systems made of self-propelled units are widespread in nature, and Active Brownian particles (ABPs) are one of the simplest such system The authors theoretically and numerically investigate the collective assembly of ABPs finding a new re-entrant phase that enables motility-induced phase separation, which is dependent solely on activity.

TDP-43 proteinopathies including frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative disorders characterized by aggregation and mislocalization of the nucleic acid-binding protein TDP-43 and subsequent neuronal dysfunction. Here, we developed endogenous models of sporadic TDP-43 proteinopathy based on the principle that disease-associated TDP-43 acetylation at lysine 145 (K145) alters TDP-43 conformation, impairs RNA-binding capacity, and induces downstream mis-regulation of target genes. Expression of acetylation-mimic TDP-43K145Q resulted in stress-induced nuclear TDP-43 foci and loss of TDP-43 function in primary mouse and human-induced pluripotent stem cell (hiPSC)-derived cortical neurons. Mice harboring the TDP-43K145Q mutation recapitulated key hallmarks of FTLD, including progressive TDP-43 phosphorylation and insolubility, TDP-43 mis-localization, transcriptomic and splicing alterations, and cognitive dysfunction. Our study supports a model in which TDP-43 acetylation drives neuronal dysfunction and cognitive decline through aberrant splicing and transcription of critical genes that regulate synaptic plasticity and stress response signaling. The neurodegenerative cascade initiated by TDP-43 acetylation recapitulates many aspects of human FTLD and provides a new paradigm to further interrogate TDP-43 proteinopathies.

Introduction: Approximately 2% of the U.S. population identifies as transgender, and transgender people experience disproportionate rates of cardiovascular disease mortality. However, widely used cardiovascular disease risk estimators have not been validated in this population. This study sought to determine the impact on statin therapy recommendations using 3 different approaches to operationalizing sex in the American Health Association/American College of Cardiology Pooled Cohort Equation Risk Estimator. Methods: This is a cross-sectional analysis of baseline clinical data from LITE Plus, a prospective cohort study of Black and/or Latina transgender women with HIV. Data were collected from October 2020 to June 2022 and used to calculate Pooled Cohort Equation scores. Results: The 102 participants had a mean age of 43 years. A total of 88% were Black, and 18% were Latina. A total of 79% were taking gender-affirming hormones. The average Pooled Cohort Equation risk score was 6% when sex assigned at birth was used and statins would be recommended for the 31% with Pooled Cohort Equation >7.5%. The average risk score was 4%, and 18% met the criteria for statin initiation when current gender was used; the mean risk score was 5%, and 22% met the criteria for statin initiation when current hormone therapy was used. Conclusions: Average Pooled Cohort Equation risk scores vary substantially depending on the approach to operationalizing the sex variable, suggesting that widely used cardiovascular risk estimators may be unreliable predictors of cardiovascular disease risk in transgender populations. Collection of sex, gender, and hormone use in longitudinal studies of cardiovascular health is needed to address this important limitation of current risk estimators.

Abstract Non-compliance to intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy can result in increased disease activity in neovascular age-related macular degeneration (nAMD). Our study aims to determine effects of unplanned delay in anti-VEGF injection treatment for nAMD. This retrospective observational study included patients with delays in receiving intravitreal injections for nAMD treatment from March to May 2020 by at least 21 days. Baseline demographic and clinical characteristics, visual acuity (VA), central macular thickness (CMT) measured on optical coherence tomography (OCT), and duration of delayed treatment were analyzed for 3 time points, the pre-delay visit (v1) and post-delay visits (v2 and v3). Data were compared to age-matched controls treated for nAMD in 2019 without delay. Demographic characteristics were compared using two-sample t-tests for continuous variables and Pearson’s chi-square tests for categorical variables. For the two primary outcomes of interest, VA and CMT, means and standard deviations were reported for each combination of group and time. Each outcome was modeled using a linear mixed model with the group, time and group-time interaction as fixed effects. A total of 69 patients (99 eyes) in the treatment delay group and 44 patients (69 eyes) in the control group were identified. Statistically significant differences between control and delayed groups were detected for VA (difference in mean logMAR = 0.16; 95% CI 0.06, 0.27; p = 0.002) and CMT (difference in mean CMT = 29; 95% CI 12, 47; p = 0.001) at v2. No differences were detected for v1 and v3 time points for both outcomes. An unplanned delay in intravitreal injection treatment for nAMD resulted in an increase in CMT and worsening of VA compared to controls observed at v2. At v3, CMT and VA recovered to near v1 levels. This study demonstrates that a one-time, brief interruption in treatment for nAMD results in reversible, temporary worsening.

Hydrogen–oxygen vehicle fuel cells have high research and development prospect because of their advantages of environmental protection, pollution-free and high energy conversion efficiency. Air compressor is an important part of vehicle fuel cell system. Dry twin screw compressors have been applied very well in bus fuel cell system. Aiming at the characteristics of low pressure ratio and large flow rate of fuel cell air compressors, a kind of 3–5 twin screw air compressor profile was designed, and the design method was given.

As a simple way to enhance catalytical performance, it has long been believed that catalyst loading increases the number of sites available for reaction. The overall reaction rate will increase and saturate eventually as catalyst loading increases. Here, we report a counterintuitive optimal catalyst loading for electrocatalytic carbon dioxide reduction (eCO_{2}R) on nanocatalysts. Numerical analysis based on a comprehensive kinetic model reveals that nanocurved electric field (NEF) resulted from the comparable size of nanocatalysts and the electric double layer can essentially affect eCO_{2}R. While NEF induces extra mass transfer raising the overall reaction rate for low catalyst loading, such extra mass transfer is sharply reduced due to the overlap of NEF for high catalyst loading. These findings challenge the conventional physical picture of loading-dependent overall catalytical performance, and provide a new concept for design of nanocatalysis.

Electrocatalytic CO2 reduction reaction (CO2RR) powered by renewable electricity offers an efficient way of capturing CO2 from the environment to mitigate the climate challenge and produce carbon-neutral hydrocarbon fuels. As the electrocatalysts downsize to the nanoscale, the effect of local concentration around catalysts turns to be significant for the performance of CO2 reduction. Herein, we review nanoscale local concentration effect on electrocatalytic CO2RR by summing up some recent related catalyst design strategies and their underlying mechanisms, providing a perspective for future catalyst design taking such an effect into account.

Despite its prominent therapeutic efficacy, chemotherapy has raised serious concerns due to the severe adverse effects and multidrug resistance evoked, which propels the search for safe and green therapeutic agents. BAMLET (bovine α-lactalbumin made lethal against tumor cell) is a well-known protein-based anticancer agent of selective tumoricidal activity. Here, we prepared oleic acid-modified mesoporous silica nanoparticles (OA-MSNs) conjugated with bovine α-lactalbumin, a lipoprotein complex resembling BAMLET formed on the surface of MSNs (MSN-BAMLET) to load the anticancer drug of docetaxel (DTX). Compared to that of OA-MSNs/DTX, the obtained MSN-BAMLET/DTX with a sustained and pH-responsive drug release behaviors exhibited good biocompatibility and enhanced cytotoxic effect against cancer cells. Moreover, the presence of lipoprotein complex in MSN-BAMLET contributed to the improved dispersion of the composite in solution and the inhibitory effect on the migration of cancer cells. Furthermore, the adsorption profiles of protein corona on the obtained nanoparticles were analyzed. It was found that the marked low amount and abundance of plasma proteins were adsorbed on the α-lactalbumin coated siliceous composite demonstrated its long circulation property. Finally, in vivo study showed that MSN-BAMLET/DTX contributed to the effective cancer ablation and the prolonged survival. Therefore, the constructed MSN-BAMLET of the mesoregular structure and peculiar tumoricidal effect provides a manipulable nanoplatform as drug nanocarrier for therapeutic applications.

Novel magnetic carbon microtube-based solid acid was synthesized via the carbonization of FeCl3-doped willow catkin and benzenediazoniumsulfonate acid-based sulfonation. The biomass willow catkin provided the special microtube structure and the high surface area of 215 m2/g for the novel solid acid. The microtube structure was well conserved during the mild carbonization (400 °C) and sulfonation process. The large number of acidic sites (2.3 mmol/g) on the microtube surface was quite accessible to reactants. Its magnetic properties offered a simple separation process. The novel solid acid showed very high activity for biodiesel synthesis, using cooking oils as raw material, which gave a total yield of 99% and free fatty acid conversion of 98.7% under mild conditions (70 °C). The facile synthetic process, high activity, high stability, and high recovery simplicity were the main properties of the novel magnetic solid acid, which is one of the best choices for biodiesel synthesis.

Motility-induced phase separation (MIPS) is of great importance and has been extensively researched in overdamped systems, nevertheless, what impacts inertia will bring on kinetics of MIPS is lack of investigation. Here, we find a nucleation-like MIPS instead of spinodal decomposition in the overdamped case, i.e. not only the phase transition changes from continuous to discontinuous, but also the formation of clusters does not exhibit any coarsening regime. This remarkable kinetics of MIPS stems from a competition between activity-induced accumulation of particles and inertia-induced suppression of clustering process. More interestingly, the discontinuity of MIPS still exists even when the ratio of particle mass to the friction coefficient reduces to be very small such as 10 ^−4 . Our findings emphasize the importance of inertia induced kinetics of MIPS, and may open a new perspective on understanding the nature of MIPS in active systems.

As biochemical systems may frequently suffer from limited energy resources, so that internal molecular fluctuation has to be utilized to induce random rhythm, it is still a great theoretical challenge to understand the elementary principles for biochemical systems with limited energy resources to maintain phase accuracy and phase sensitivity. Here, we address the issue by deriving the energy-accuracy and the sensitivity-accuracy trade-off relations for a general biochemical model, analytically and numerically. We find that biochemical systems have a much lower energy cost by using noise-induced oscillations to keep almost equal efficiency to maintain precise processes compared with the energy cost using normal oscillations, clearly elucidating a survival mechanism when energy resources are limited. Moreover, an optimal system size is predicted where both the highest sensitivity and highest accuracy can be reached at the same time, providing a new strategy for the design of biological networks with limited energy sources.

Purpose: To determine the effect of formononetin (FMNT) in the proliferation, drug resistance, and DNA damage of myeloproliferative neoplasm (MPN), and to evaluate the potential of FMNT as a therapeutic target. Methods: Cell viability curves and colony formation assays were used to characterize the proliferation of HEL or HEL/R cells. Flow cytometry was conducted to assess the apoptosis of HEL or HEL/R cells, while western blotting was performed to evaluate the expressions of DNA H2AX, DNA-PK, and Rad51, which are indicative of DNA damage, and the phosphorylation levels of JAK2 and STAT3 were determined. Results: Formononetin (FMNT) suppressed cell proliferation of HEL cells in a dose-dependent manner. It significantly reduced colony formation and promoted apoptosis of HEL cells (p < 0.05). For HEL/R cells, FMNT treatment significantly reduced cell viability, and resistance, and promoted apoptosis. Moreover, FMNT elevated H2AX levels and significantly reduced the expressions of DNA-PK and Rad51 in TG101209 (TG)-induced JAK-TKI-resistant cells (p < 0.05). Furthermore, FMNT decreased JAK2 and STAT3 phosphorylation in JAK-TKI-resistant cells. Conclusion: Treatment with FMNT represses proliferation, promotes apoptosis, weakens JAK-TKI resistance, and strengthens DNA damage in MPN cells by suppressing JAK/STAT3 pathway. This suggests that FMNT is a potential therapeutic candidate for the treatment of MPN. [ABSTRACT FROM AUTHOR]

To investigate the characteristics of blood lipid metabolism in twin pregnancy combined with gestational diabetes mellitus (GDM) or pregnancyinduced hypertension (PIH). This study retrospectively analyzed 96 cases of twin pregnancy and 232 cases of full-term singleton pregnancy. General data and blood lipid levels, including triglyceride (TG) and total cholesterol (TC), between twin and singleton pregnancies were compared. Blood lipid levels between GDM (PIH) and non-GDM (non-PIH) groups in twin pregnancy were compared. The TG level for twin pregnancy was higher than that for singleton pregnancy (p<0.05), while there was no significant difference in the TC level between them (p>0.05). The TG level in the GDM group was higher than that in the non-GDM group (p<0.05), while the TC level in the GDM group was not different from that in the non-GDM group (p>0.05). The TG level in the PIH group was higher than that in the non-PIH group (p<0.05), while there was no difference in the TC level between them (p>0.05). Logistic regression analysis showed that age was a risk factor for GDM and PIH in singleton and twin pregnancies. The lipid levels in twin pregnancy increased with the increase of gestational age, and the TG level in twin pregnancy complicated with GDM or PIH was higher than that in twin pregnancy without GDM or PIH, indicating that the blood lipid metabolism was related to the occurrence of GDM and PIH in twin pregnancy to some extent. [ABSTRACT FROM AUTHOR]

Grain filling is a crucial process that affects yield in rice (Oryza sativa L.). Auxin biosynthesis and signaling are closely related to rice yield; therefore, it is important to understand the effects of auxin biosynthesis on rice grain filling to improve crop yield. In this study, we used physiological and molecular strategies to identify the roles of auxin in rice grain filling. Exogenous application of auxin (IAA) or auxin analogues (2, 4-D) to young spikelets and flag leaves improved the seed-setting rate and yield per spike. Furthermore, real-time quantitative PCR assays confirmed that nine members of the OsYUCCA family of auxin biosynthetic genes were upregulated during grain filling, implication that auxin biosynthesis plays a major role in grain development. The specific expression of either Arabidopsis AtYUCCA1 or OsYUCCA2 in the endosperm or leaves resulted in increased expression of OsIAA genes and auxin content of seeds, as well as increased grain filling and seed-setting rate. This result establishes that the auxin content in grains and leaves is important for grain development. Our findings further highlight the potential applications for improving rice yield by elevating targeted gene expression in specific tissues. [ABSTRACT FROM AUTHOR]

Polymer translocation through nanopores into a crowded environment is of ubiquitous importance in many biological processes. Here we investigate polymer translocation through a nanopore into an active bath of self-propelled particles in two-dimensional space using Langevin dynamics simulations. Interestingly, we find that the mean translocation time <τ> can show a bell-shape dependence on the particle activity Fa at a fixed volume fraction ɸ, indicating that the translocation process may become slower for small activity compared to the case of the passive media, and only when the particle activity becomes large enough can the translocation process be accelerated. In addition, we also find that <τ> can show a minimum as a function of ɸ if the particle activity is large enough, implying that an intermediate volume fraction of active particles is most favorable for the polymer translocation. Detailed analysis reveals that such nontrivial behaviors result from the two-fold effect of active bath: one that active particles tend to accumulate near the pore, providing an extra pressure hindering the translocation, and the other that they also aggregate along the polymer chain, generating an effective pulling force accelerating the translocation. Such results demonstrate that active bath plays rather subtle roles on the polymer translocation process. [ABSTRACT FROM AUTHOR]

The dynamics of point-like Brownian particles in a periodic confined channel with oscillating boundaries has been studied. Directional transport (DT) behavior, characterized by net displacement along the horizontal direction, is observed even without external force which is necessary for the conventional DT where the boundaries are static. For typical parameter values, the average velocity Vt of DT reaches a maximum with the variation of the noise intensity D, being alike to the phenomenon of stochastic resonance. Interestingly, we find that Vt shows nontrivial dependences on the particle gravity G depending on the noise level. When the noise is large, Vt increases monotonically with G indicating that heavier particle moves faster, while for small noise, Vt shows a bell-shape dependence on G, suggesting that a particle with an intermediate weight may move the fastest. Such results were not observed for DT in a channel with static boundaries. To understand these findings, we have adopted an effective one-dimensional coarsening description, which facilitates us to introduce an effective entropic force along the horizontal direction. The average force is apparently nonzero due to the oscillatory boundary, hence leading to the net transport, and it shows similar dependences as Vt on the noise intensity D and particle gravity G. The dependences of the DT behavior on other parameters describing the oscillatory channel have also been investigated, showing that DT is more pronounced for larger oscillation amplitude and frequency, and asymmetric geometry within a channel period and phase difference between neighboring periods are both necessary for the occurrence of DT. [ABSTRACT FROM AUTHOR]

Epitaxial growth via chemical vapor deposition is considered to be the most promising way towards synthesizing large area graphene with high quality. However, it remains a big theoretical challenge to reveal growth kinetics with atomically energetic and large-scale spatial information included. Here, we propose a minimal kinetic Monte Carlo model to address such an issue on an active catalyst surface with graphene/substrate lattice mismatch, which facilitates us to perform large scale simulations of the growth kinetics over two dimensional surface with growth fronts of complex shapes. A geometry-determined large-scale growth mechanism is revealed, where the rate-dominating event is found to be C1-attachment for concave growth-front segments and C5-attachment for others. This growth mechanism leads to an interesting time-resolved growth behavior which is well consistent with that observed in a recent scanning tunneling microscopy experiment. [ABSTRACT FROM AUTHOR]

We have studied the dynamics of Brownian particles in a confined geometry of dumbbell-shape with periodically oscillating walls. Entropic stochastic resonance (ESR) behavior, characterizing by a maximum value of the coherent factor Q at some optimal level of noise, is observed even without external periodic force in the horizontal direction, which is necessary for conventional ESR where the wall is static and the particle is subjected to the force. Interestingly, the ESR can be remarkably enhanced by the particle gravity G, in contrast to the conventional case. In addition, Q decreases (increases) with G in the small (large) noise limit, respectively, while it non-monotonically changes with G for moderate noise levels. We have applied an effective 1D coarsening description to illustrate such a nontrivial dependence on G, by investigating the property of the 1D effective potential of entropic nature and paying special attention to the excess part resulting from the boundary oscillation. Dependences of the ESR strength with other related parameters are also discussed. [ABSTRACT FROM AUTHOR]

Immunosensing methods are biosensing techniques based on specific recognition of an antigen -antibody immunocomplex, which have become commonly used in safeguarding public health. Taking advantage of antibody-related biotechnological advances, the utilization of an antigen-binding fragment of a heavy-chain-only antibody termed as 'nanobody' holds significant biomedical potential. Compared with the conventional full-length antibody, a single-domain nanobody retaining cognate antigen specificity possesses remarkable physicochemical stability and structural adaptability, which enables a flexible and efficient molecular design of the immunosensing strategy. This minireview aims to summarize the recent progress in immunosensing methods using nanobody targeting tumor markers, environmental pollutants, and foodborne microbes. [ABSTRACT FROM AUTHOR]

Auxiliary training method of martial arts based on Ecological Science is proposed in this paper, which takes a university martial arts student as the research object, it takes the cognitive training method, metacognitive strategy and image training method to carry on the experiment analysis to the martial cadets. The results show that the cognitive training method can give full play to the cognitive function of the students, deepen the students' understanding of technology, and speed up the mastery of action techniques. After the use of metacognitive strategies, the students with high metacognition ability and low metacognitive ability are used in the study. The performance of the staff is relatively low, the high metacognition level has a greater impact on the performance than the low cognitive level, the imagery training method is beneficial to alleviate the cognitive anxiety and enhance the state of self-confidence. [ABSTRACT FROM AUTHOR]

BiOCl-SiO2 KIT-6 composite materials with raspberry-like structures are facilely prepared under hydrothermal conditions. The mesoporous siliceous support of SiO2 KIT-6-incorporated BiOCl with enlarged yet refined surface morphology characterized by physiochemical methods exhibits an improved electrochemical performance. A sensitive electrochemical detection method of cadmium concentration using square wave anodic stripping voltammetry was developed based on BiOCl-SiO2 KIT-6 composite-modified glassy carbon electrodes, which displayed wide linear ranges of 0.5 to 10 μg/L and 10 to 300 μg/L and a detection limit of 65 ng/L. The sensitive, versatile and eco-friendly sensor was successfully applied for the determination of cadmium-spiked human blood samples. [ABSTRACT FROM AUTHOR]

Formation of spiral waves in a bursting media is investigated. Due to the multiple timescale oscillation of the local dynamics, an interesting substructure of traveling wave (STW) is observed in the spiral arm. As a result of the special moving media formed by neurons in the spiral arm, STWs propagate from the spiral tip to far field with an increasing wave length and move faster along the front of the spiral arm than along the back, leading to the formation of fragments in STWs. Moreover, we find that a sharp change of stimulus current can lead to backfiring of STWs, which may break the spiral wave front and further result in the formation of a multi-spiral pattern. [ABSTRACT FROM AUTHOR]

Although the corresponding carbon-metal interactions can be very different, a similar nonlinear growth behavior of graphene has been observed for different metal substrates. To understand this interesting experimental observation, a multiscale "standing-on-the-front" kinetic Monte Carlo study is performed. An extraordinary robust geometry effect is identified, which solely determines the growth kinetics and makes the details of carbon-metal interaction not relevant at all. Based on such a geometry-determined mechanism, the epitaxial growth behavior of graphene can be easily predicted in many cases. As an example, the orientation-sensitive growth kinetics of graphene on an Ir(111) surface has been studied. Our results demonstrate that the lattice mismatch pattern at the atomic level plays an important role in macroscopic epitaxial growth. [ABSTRACT FROM AUTHOR]

As a two-dimensional material, graphene can be obtained via epitaxial growth on a suitable substrate. Recently, an interesting nonlinear behavior of graphene growth has been observed on some metal surfaces, but the underlying mechanism is still elusive. Taking the Ir(111) surface as an example, we perform a mechanistic study on graphene growth using a combined approach of first-principles calculations and kinetic Monte Carlo (kMC) simulations. Small carbon clusters on the terrace or at step sites are studied first. Then, we investigate how these small carbon species are attached to graphene edges. Generally, attachment of carbon atoms is thermodynamically favorable. However, due to substrate effect, there are also some edge sites where graphene growth must proceed via cluster attachment. The overall growth rate is determined by these cluster attachment processes, which have a much lower chance of happening compared to the monomer attachment. On the basis of such an inhomogeneous growth picture, kMC simulations are performed by separating different time scales, and the experimentally found quintic-like behavior is well reproduced. Different nonlinear growth behaviors are predicted for different graphene orientations, which is consistent with previous experiments. Inhomogeneity induced by lattice mismatch revealed in this study is expected to be a universal phenomenon and will play an important role in the growth of many other heteroepitaxial systems. [ABSTRACT FROM AUTHOR]

We discuss stochastic thermodynamics (ST) for delayed Langevin systems in this paper. By using the general principles of ST, the first-law-like energy balance and trajectory-dependent entropy s(t) can be well defined in a way that is similar to that in a system without delay. Because the presence of time delay brings an additional entropy flux into the system, the conventional second law <Δstot> 0 no longer holds true, where Δstot denotes the total entropy change along a stochastic path and <•> stands for the average over the path ensemble. With the help of a Fokker-Planck description, we introduce a delay-averaged trajectory-dependent dissipation functional η[χ(t)] which involves the work done by a delay-averaged force F(x,t) along the path χ(t) and equals the medium entropy change Δsm[x(t)] in the absence of delay. We show that the total dissipation functional R=Δs+η, where Δs denotes the system entropy change along a path, obeys ⩾0, which could be viewed as the second law in the delayed system. In addition, the integral fluctuation theorem =1 also holds true. We apply these concepts to a linear Langevin system with time delay and periodic external force. Numerical results demonstrate that the total entropy change <Δstot> could indeed be negative when the delay feedback is positive. By using an inversing-mapping approach, we are able to obtain the delay-averaged force F(x,t) from the stationary distribution and then calculate the functional R as well as its distribution. The second law ⩾0 and the fluctuation theorem are successfully validated. [ABSTRACT FROM AUTHOR]

Background. During the outbreak of the emergent severe acute respiratory syndrome (SARS) infection, >30% of the ∼8000 infected persons were health care workers. The highly infectious nature of SARS coronavirus (SARS- CoV) compelled our pathologists to consider biosafety issues in the autopsy room and for tissue processing procedures. Methods. A specially designed biosafety level 3 (BSL- 3) autopsy laboratory was constructed and divided into a clean area, a semicontaminated area, a contaminated area, and 2 buffer zones. High-efficiency particulate air filters were placed in the air supply and exhaust systems. Laminar air flow was from the clean areas to the less clean areas. The negative pressures of the contaminated, semicontaminated, and clean areas were approximately -50 pa, -25 pa, and -5 pa, respectively. Personal protective equipment, including gas mask, impermeable protective clothing, and 3 layers of gloves worn during autopsies; the equipment was decontaminated before it was allowed to exit the facility. Strict BSL-3 practices were followed. Results. When a given concentration of particulate sarin simulant was introduced into the contaminated area, it could not be detected in either the semicontaminated area or clean area, and particles >0.3 μm in size were not detected in the exhaust air. A total of 16 complete postmortem examinations for probable and suspected SARS were performed during a 2-month period. Of these, 7 reported confirmed cases of SARS. None of the 23 pathologists and technicians who participated in these autopsies was infected with SARS-CoV. Conclusions. Our experience suggests that BSL-3 laboratory operating principles should be among the special requirements for performing autopsies of contaminated bodies and that they can safeguard the clinicians and the environment involved in these procedures. [ABSTRACT FROM AUTHOR]

We have studied spatial and temporal dynamic heterogeneity (DH) in a system of hard-sphere particles, subjected to active forces with constant amplitude and random direction determined by rotational diffusion with correlation time τ. We have used a variety of observables to characterize the DH behavior, including the deviation from standard Stokes-Einstein (SE) relation, a non-Gaussian parameter α2(Δt) for the distribution of particle displacement within a certain time interval Δt, a four-point susceptibility χ4(Δt,ΔL) for the correlation in dynamics between any two points in space separated by distance ΔL within some time window Δt, and a vector spatial-temporal correlation function Svec(R,Δt) for vector displacements within time interval Δt of particle pairs originally separated by R. By mapping the particle motion into a continuous-time random walk with constant jump length, we can obtain the average waiting time ⟨tx⟩∝Ds-1 and persistence time ⟨tp⟩∝η, with Ds the self-diffusion coefficient and η the shear viscosity, such that the observable λ=⟨tp⟩/⟨tx⟩∝Dsη can be calculated as a function of the control parameter τ to show how it deviates from its SE value λ0. Interestingly, we find λ/λ0 shows a nonmonotonic behavior for large volume fraction φa, wherein λ/λ0 undergoes a minimum at a certain intermediate value of τ, indicating that both small and large particle activity may lead to strong DH. Such a reentrance phenomenon is further demonstrated in terms of the non-Gaussian parameters α2, four-point susceptibility χ4, and vector spatiotemporal correlation functions Svec, respectively. Detail analysis shows that it is the competition between the dual roles of particle activity, namely, activity-induced higher effective temperature and activity-induced clustering, that leads to such nontrivial nonmonotonic behaviors. In addition, we find that DH may also show a maximum level at an intermediate value of φa if τ is large enough, implying that a more crowded system may be less heterogeneous than a less crowded one for a system with high particle activity. [ABSTRACT FROM AUTHOR]

We use a kinetic mode-coupling theory (MCT) combining with generalized Langevin equation (GLE) to study the diffusion and conformational dynamics of a bead-spring Rouse chain (RC) dissolved in porous media. The media contains fluid particles and immobile matrix ones wherein the latter leads to the lack of translational invariance. The friction kernel ζ (t) used in the GLE can be obtained directly by adopting a simple density-functional approach in which the density correlators calculated by MCT equations of porous media serve as inputs. Due to cage effects generated by surrounding particles, ζ (t) shows a very long tail memory in the high volume fraction of fluid and matrix. It is found that the long-time center-of-mass diffusion constant DCM of the RC decreases with the increment of volume fraction, influencing more strongly by the matrix particles than by the fluid ones. The auto-correlation function (ACF) of the end-to-end distance fluctuation can also be calculated theoretically based on GLE. Of particular interest is that the power-law region of ACF has a nearly fixed length in logarithmic scale when it shifts to longer time range, with increasing the volume fraction of media particles. Moreover, the effect of lack of translational invariance has been investigated by comparing the results between fluid-matrix and pure fluid cases under identical total volume fraction. [ABSTRACT FROM AUTHOR]