Controllable Synthesis of Porous and Hollow Nanostructured Catalyst Particles and Their Soot Oxidation.

The introduction of macroporous structures into three-way catalysts (TWCs) through polymer template-assisted spray drying has attracted attention because of its enhanced gas diffusion and catalytic performance. However, the surface charge effect of polymeric template components has not been investigated to control the structure of the TWC particles during synthesis. Thus, this study investigated the effect of template surface charges on the self-assembly behavior of TWC nanoparticles (NPs) during drying. The self-assembly of TWC NPs and polymer particles with different charges produced a hollow structure, whereas using the same charges generated a porous one. Consequently, the mechanism of particle self-assembly during drying and final structure particle formation is proposed in this study. Here, porous TWC particles demonstrated a faster oxidation of soot particles than that of hollow-structured particles. This occurred as a result of the larger contact area between the catalyst surface and the solid reactant. Our findings propose a fundamental self-assembly mechanism for the formation of different TWC structures, thereby enhancing soot oxidation performance using macroporous structures.

Designing the Macroporous Structure of Three-Way Catalyst Particles: The Influence of Template Concentration on Framework Thickness and Mass Transfer.

Mass transfer is an essential process that can extend the performance and utilization of nanoporous materials in various applications. Therefore, improving mass transfer in nanoporous materials has always attracted much interest, and macroporous structures are currently being studied to enhance mass transfer performance. The introduction of macroporous structures into three-way catalysts (TWC), which are widely utilized to control the emission of polluted gases from vehicles, provides the potential to enhance their mass transfer property and catalytic performance. However, the formation mechanism of macroporous TWC particles has not yet been investigated. On the other hand, the influence of the framework thickness of the macroporous structure on the mass transfer enhancement is still unclear. Therefore, this report investigates the particle formation and framework thickness of the macroporous TWC particles synthesized using the template-assisted aerosol process. The formation of macroporous TWC particles was precisely controlled and investigated by altering the size and concentration of the template particles. The template concentration played a crucial role in maintaining the macroporous structure and controlling the framework thickness between the macropores. Based on these results, a theoretical calculation showing the influence of template concentration on the particle morphology and framework thickness was developed. The final results showed that increasing the template concentration can positively affect the nanoporous material's framework thickness reduction and mass transfer coefficient improvement.

Catalytic allylic oxidation of internal alkenes to a multifunctional chiral building block.

The stereoselective oxidation of hydrocarbons is one of the most notable advances in synthetic chemistry over the past fifty years. Inspired by nature, enantioselective dihydroxylations, epoxidations and other oxidations of unsaturated hydrocarbons have been developed. More recently, the catalytic enantioselective allylic carbon-hydrogen oxidation of alkenes has streamlined the production of pharmaceuticals, natural products, fine chemicals and other functional materials. Allylic functionalization provides a direct path to chiral building blocks with a newly formed stereocentre from petrochemical feedstocks while preserving the olefin functionality as a handle for further chemical elaboration. Various metal-based catalysts have been discovered for the enantioselective allylic carbon-hydrogen oxidation of simple alkenes with cyclic or terminal double bonds. However, a general and selective allylic oxidation using the more common internal alkenes remains elusive. Here we report the enantioselective, regioselective and E/Z-selective allylic oxidation of unactivated internal alkenes via a catalytic hetero-ene reaction with a chalcogen-based oxidant. Our method enables non-symmetric internal alkenes to be selectively converted into allylic functionalized products with high stereoselectivity and regioselectivity. Stereospecific transformations of the resulting multifunctional chiral building blocks highlight the potential for rapidly converting internal alkenes into a broad range of enantioenriched structures that can be used in the synthesis of complex target molecules.

Reduced Time to Surgery and Prophylactic Fasciotomy May Result in Improved Outcomes in Popliteal Artery Injuries.

BACKGROUND: Popliteal artery injuries are uncommon and often result in limb loss or long-term limb dysfunction. The aims of this study were (1) to evaluate the association between predictors and outcomes and (2) to validate the rational of systematic early fasciotomy. METHODS: This retrospective cohort study included 122 patients (80% men, n = 100) who underwent surgery for popliteal artery injuries from October 2018 to March 2021 in southern Vietnam. Primary outcomes included primary and secondary amputation. The associations between predictors and primary amputation were analyzed using logistic regression models. RESULTS: Among the 122 patients, 11 (9%) underwent primary amputation, while 2 (1.6%) had secondary amputation. Longer time to surgery was associated with increased odds of amputation (odds ratio = 1.65; 95% confidence interval, 1.2 to 2.2 for every 6 hr). Severe limb ischemia was also associated with a 50-fold increase in the risk of primary amputation (adjusted odds ratio = 49.9; 95% confidence interval, 6 to 418, P = 0.001). Furthermore, 11 patients (9%) without signs of severe limb ischemia and acute compartment syndrome on admission were found to have myonecrosis of at least one muscle compartment during fasciotomy. CONCLUSIONS: The data suggest that among patients with popliteal artery injuries, prolonged time before surgery and severe limb ischemia are associated with increased risk of primary amputation, whereas early fasciotomy may lead to improved outcomes.

Bayesian merging of numerical modeling and remote sensing for saltwater intrusion quantification in the Vietnamese Mekong Delta.

Saltwater intrusion has become one of the most concerning issues in the Vietnamese Mekong Delta (VMD) due to its increasing impacts on agriculture and food security of Vietnam. Reliable estimation of salinity plays a crucial role to mitigate the impacts of saltwater intrusion. This study developed a hybrid technique that merges satellite imagery with numerical simulations to improve the estimation of salinity in the VMD. The salinity derived from Landsat images and by numerical simulations was fused using the Bayesian inference technique. The results indicate that our technique significantly reduces the uncertainties and improves the accuracy of salinity estimates. The Nash-Sutcliffe coefficient is 0.74, which is much higher than that of numerical simulation (0.63) and Landsat estimation (0.6). The correlation coefficient between the ensemble and measured salinity is relatively high (0.88). The variance of the ensemble salinity errors (5.0 ppt2) is lower than that of Landsat estimation (10.4 ppt2) and numerical simulations (9.6 ppt2). The proposed approach shows a great potential to combine multiple data sources of a variable of interest to improve its accuracy and reliability wherever these data are available.

A Sustainable Approach for Preparing Porous Carbon Spheres Derived from Kraft Lignin and Sodium Hydroxide as Highly Packed Thin Film Electrode Materials.

A green synthetic strategy to design biomass-derived porous carbon electrode materials with precisely tailored structure and morphology has always been a challenging goal because these materials can fulfill the demands of next-generation supercapacitors and other electrochemical devices. Potassium hydroxide (KOH) is extensively utilized as an activator since it can produce porous carbon with high specific surface area and well-developed porous channels. The exploitation of sodium hydroxide (NaOH) as an activating agent is less referenced in the literature, although it offers some advantages over KOH in terms of low cost, less corrosiveness, and simple handling procedure, all of which are appealing particularly from an industrial viewpoint. The motivation for this present study is to fabricate porous carbon spheres in a sustainable manner via a spray drying approach followed by a carbonization process, using Kraft lignin as the carbon precursor and NaOH as an alternative activation agent instead of the high-cost and high-corrosive KOH for the first time. The structure of carbon particles can be accurately transitioned from a compact to hollow structure, and the surface textural properties can be easily tuned by altering the NaOH concentration. The obtained porous carbon spheres were applied as highly packed thin film electrode materials for supercapacitor devices. The specific capacitance value of porous carbon spheres with a highly compact structure (high packing density) is 66.5 F g-1, which is higher than that of commercial activated carbon and other biomass-derived carbon. This work provides a green processing for producing low-cost and environment-friendly porous carbon spheres from abundant Kraft lignin and important insight for selecting NaOH as an activator to tailor the morphology and structure, which represents an economical and sustainable approach for energy storage devices.

A Dynamic Visualization Tool of Local Trends in Heart Disease and Stroke Mortality in the United States.

Efforts in the US to prevent and treat cardiovascular disease (CVD) contributed to large decreases in death rates for decades; however, in the last decade, progress has stalled, and in many counties, CVD death rates have increased. Because of these increases, there is heightened urgency to disseminate high-quality data on the temporal trends in CVD mortality. The Local Trends in Heart Disease and Stroke Mortality Dashboard is an online, interactive visualization of US county-level death rates and trends for several CVD outcomes across stratifications of age, race and ethnicity, and sex. This powerful visualization tool generates national maps of death rates and trends, state maps of death rates and trends, county-level line plots of annual death rates, and bar charts of percentage changes. County-level death rates and trends were estimated by applying a Bayesian spatiotemporal model to data obtained from the National Vital Statistics System of the National Center for Health Statistics and US Census bridged-race intercensal estimates for the years 1999 through 2019. The Local Trends in Heart Disease and Stroke Mortality Dashboard makes it easy for public health practitioners, health care providers, and community leaders to monitor county-level spatiotemporal trends in CVD mortality by age group, race and ethnicity, and sex and provides key information for identifying and addressing local health inequities in CVD mortality trends.

Morphological dependent effect of cell-free formed supramolecular fibronectin on cellular activities.

Fibrillar fibronectin (FFN), an active form of fibronectin (FN), plays important roles in various cellular processes. Our goal is to investigate effect of FFN morphology on cellular behaviors. Plasma FN at two concentrations was cross-linked into FFN by dialysis against 2 M urea followed by morphological analysis under Scanning Electron Microscopy. To evaluate effect of FFN morphology, fibroblasts were cultured on FN or different FFNs. Fibroblast behaviors including adhesion, spreading, and migration were evaluated. Our data showed that FN fibrillogenesis was dependent on FN concentration. At high concentrations (0.75 mg/mL), large FFN approximately 2.167 + 0.875 µm in diameter were formed with attached nodular structures and rough surface. In contrast, smooth surface FFN fibrils with diameter of 1.886 + 0.412 µm were formed from FN at 0.25 mg/mL. Cellular assays revealed morphological dependent biological effects of different FFNs. Fibroblast separately adhered to native FN and remained spherical while on FFN, cells attached with higher quantity and showed spreading morphology. A synergistic ligand interaction of integrin α5ß1 and αvß3 was observed in cell adhering on FFN. Cell migration results showed that large FFN decreased migration rate while small FFN did not. Taken together, our data draws new attention towards controlling biological function of FN by its fibrillar structure.

Underestimated MJO variability in CMIP6 models.

The Madden-Julian Oscillation (MJO) is the leading mode of intra-seasonal climate variability, having profound impacts on a wide range of weather and climate phenomena. Here, we use a wavelet-based spectral Principal Component Analysis (wsPCA) to evaluate the skill of 20 state-of-the-art CMIP6 models in capturing the magnitude and dynamics of the MJO. By construction, wsPCA has the ability to focus on desired frequencies and capture each propagative physical mode with one principal component (PC). We show that the MJO contribution to the total intra-seasonal climate variability is substantially underestimated in most CMIP6 models. The joint distribution of the modulus and angular frequency of the wavelet PC series associated with MJO is used to rank models relatively to the observations through the Wasserstein distance. Using Hovmöller phase-longitude diagrams, we also show that precipitation variability associated with MJO is underestimated in most CMIP6 models for the Amazonia, Southwest Africa, and Maritime Continent.

Avulsion fractures of the knee: a review of the pathophysiology, radiographic, and cross-sectional imaging features.

Knee trauma is a common presenting symptom in the emergency setting. Avulsive knee injuries are important to diagnose timely and accurately to avoid unnecessary patient morbidity. Many of these avulsive knee injuries have characteristic appearances on imaging. This article presents a comprehensive review of some of the most common types with real cases used for imaging correlation.

Stochastic lattice-based modelling of malaria dynamics.

BACKGROUND: The transmission of malaria is highly variable and depends on a range of climatic and anthropogenic factors. In addition, the dispersal of Anopheles mosquitoes is a key determinant that affects the persistence and dynamics of malaria. Simple, lumped-population models of malaria prevalence have been insufficient for predicting the complex responses of malaria to environmental changes. METHODS AND RESULTS: A stochastic lattice-based model that couples a mosquito dispersal and a susceptible-exposed-infected-recovered epidemics model was developed for predicting the dynamics of malaria in heterogeneous environments. The It[Formula: see text] approximation of stochastic integrals with respect to Brownian motion was used to derive a model of stochastic differential equations. The results show that stochastic equations that capture uncertainties in the life cycle of mosquitoes and interactions among vectors, parasites, and hosts provide a mechanism for the disruptions of malaria. Finally, model simulations for a case study in the rural area of Kilifi county, Kenya are presented. CONCLUSIONS: A stochastic lattice-based integrated malaria model has been developed. The applicability of the model for capturing the climate-driven hydrologic factors and demographic variability on malaria transmission has been demonstrated.

Consumption of edible ice contaminated with Acinetobacter, Pseudomonas, and Stenotrophomonas is a risk factor for fecal colonization with extended-spectrum ß-lactamase-producing Escherichia coli in Vietnam.

Although Vietnamese residents frequently harbor extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-E), it is unclear which foods/beverages are risk factors for acquiring these bacteria. The aim of this study was to evaluate the frequency with which edible ice served in restaurants is contaminated with antibiotic-resistant bacteria, and thereby clarify whether this product poses a risk for ESBL-E carriage in humans. Ice from restaurants in Vietnam and Japan was screened for bacteria capable of growing on agar containing cefotaxime (BG-CTX). Of the 119 BG-CTX strains isolated in Vietnam, 40%, 39%, and 12% were identified as Pseudomonas spp., Acinetobacter spp., and Stenotrophomonas maltophilia, respectively. Meanwhile, of the six such strains isolated in Japan, five were identified as Acinetobacter spp. and one as Pseudomonas spp. More than 10% of the Acinetobacter isolates exhibited cefotaxime, ceftazidime, and sulfa/trimethoprim resistance, while 21% of Pseudomonas and 14% of S. maltophilia isolates exhibited meropenem and sulfa/trimethoprim resistance, respectively. Subsequent multiplex polymerase chain reaction (PCR) analyses detected ESBL-encoding genes in 10% of the BG-CTX. Notably, feces harvested from mice administered water contaminated with BG-CTX contained E. coli harboring the blaCTX-M-9 gene. In conclusion, our findings indicate that consumption of contaminated edible ice is a risk factor for human ESBL-E carriage.

Caregiving to persons living with HIV/AIDS: experiences of Vietnamese family members.

AIMS AND OBJECTIVES: To examine the experiences of caregiving among Vietnamese family members of persons living with HIV/AIDS. BACKGROUND: As the number of persons living with HIV/AIDS increases, the need of family caregivers who can take responsibility for the home care of these persons increases. Vietnam has one of the fastest growing HIV epidemics in Asia. DESIGN: A descriptive cross-sectional study with quantitative and qualitative methods was used. METHODS: A purposive sample of 104 family caregivers, both male and female, participated voluntarily by answering a questionnaire of caregiver burden, and 20 of them participated in in-depth interview. RESULTS: Female caregivers were mainly mothers and wives while male caregivers were mainly husbands, fathers and siblings. The largest group of family caregivers reported moderate to severe burden. There was no difference between genders in total caregiver burden, but there were several differences between older and younger caregivers in some items of caregiver burden. Five categories of experiences emerged: Different types of caregiving to persons living with HIV/AIDS, cultural and religious issues associated with caregiving, keeping secret to avoid stigma and discrimination, lack of knowledge about disease and provision of care, and fear, anxiety and frustration. CONCLUSIONS: Stigma and discrimination should be decreased by providing knowledge to the general public about HIV/AIDS, in particular about ways of transmission and protection. Special knowledge should be given to family caregivers to enable them to give care to persons living with HIV/AIDS at home. This could be done through culturally appropriate training/intervention programmes in which coping methods should be included. Support group interventions should also be carried through. The results obtained can be used as baseline information. RELEVANCE TO CLINICAL PRACTICE: Health care providers should consider gender, age and culture of family members of persons living with HIV/AIDS. Knowledge about HIV/AIDS, provision of care at home and in hospital, and support groups should be developed and implemented.

Hydrazone-initiated carbene/alkyne cascades to form polycyclic products: ring-fused cyclopropenes as mechanistic intermediates.

A hydrazone-based carbene/alkyne cascade produced a variety of bridged and fused polycyclic products. NaOSiMe3 is a superior base for conversion of hydrazones to diazoalkanes. A key mechanistic intermediate, a ring-fused cyclopropene, has been isolated and characterized.

Enhancing T lineage production in aged mice: a novel function of Foxn1 in the bone marrow niche.

Foxn1 is essential for thymic organogenesis and T lymphopoiesis. Whereas reduced Foxn1 expression results in a decline in T lymphopoiesis, overexpression of Foxn1 in the thymus of a transgenic mouse model (Foxn1Tg) attenuates the age-associated decline in T lymphopoiesis. T lymphopoiesis begins with early T cell progenitors (ETP), derived from multipotent progenitors (MPP) in the bone marrow (BM). A decline in MPP and ETP numbers with age is thought to contribute to reduced T lymphopoiesis. Previously, we showed that reduced ETP number with age is attenuated in Foxn1 transgenic (Tg); whether the effect is initiated in the BM with MPP is not known. In this study, we report that Foxn1 is expressed in wild-type BM and overexpressed in Foxn1Tg. With age, the number of MPP in Foxn1Tg was not reduced, and Foxn1Tg also have a larger pool of hematopoietic stem cells. Furthermore, the Foxn1Tg BM is more efficient in generating MPP. In contrast to MPP, common lymphoid progenitors and B lineage cell numbers were significantly lower in both young and aged Foxn1Tg compared with wild type. We identified a novel population of lineage(neg/low), CD45(pos) EpCAM(pos), SCA1(pos), CD117(neg), CD138(neg), MHCII(neg) cells as Foxn1-expressing BM cells that also express Delta-like 4. Thus, Foxn1 affects both T lymphopoiesis and hematopoiesis, and the Foxn1 BM niche may function in skewing MPP development toward T lineage progenitors.

Implications for the hydrologic cycle under climate change due to the expansion of bioenergy crops in the Midwestern United States.

To meet emerging bioenergy demands, significant areas of the large-scale agricultural landscape of the Midwestern United States could be converted to second generation bioenergy crops such as miscanthus and switchgrass. The high biomass productivity of bioenergy crops in a longer growing season linked tightly to water use highlight the potential for significant impact on the hydrologic cycle in the region. This issue is further exacerbated by the uncertainty in the response of the vegetation under elevated CO(2) and temperature. We use a mechanistic multilayer canopy-root-soil model to (i) capture the eco-physiological acclimations of bioenergy crops under climate change, and (ii) predict how hydrologic fluxes are likely to be altered from their current magnitudes. Observed data and Monte Carlo simulations of weather for recent past and future scenarios are used to characterize the variability range of the predictions. Under present weather conditions, miscanthus and switchgrass utilized more water than maize for total seasonal evapotranspiration by approximately 58% and 36%, respectively. Projected higher concentrations of atmospheric CO(2) (550 ppm) is likely to decrease water used for evapotranspiration of miscanthus, switchgrass, and maize by 12%, 10%, and 11%, respectively. However, when climate change with projected increases in air temperature and reduced summer rainfall are also considered, there is a net increase in evapotranspiration for all crops, leading to significant reduction in soil-moisture storage and specific surface runoff. These results highlight the critical role of the warming climate in potentially altering the water cycle in the region under extensive conversion of existing maize cropping to support bioenergy demand.

Iodine-promoted amide formation via oxidative cleavage of indoles: novel quinazoline-4(3H)-one and tryptanthrin syntheses.

A highly efficient method for the direct construction of amide bonds via a selective cleavage of C-H and C[double bond, length as m-dash]C bonds in indole structures using an iodine-promoted approach was developed. Mechanistic studies indicated the formation of superoxide radicals obtained from molecular oxygen activation as a key intermediate step, which provided a precursor for subsequent oxidative ring-opening and intermolecular cyclization. A broad range of quinazolin-4(3H)-ones and tryptanthrins were synthesized in moderate to good yields under mild and environmentally benign conditions.

Exopolysaccharide-Treated Dendritic Cells Effectively Ameliorate Acute Graft-versus-Host Disease.

Graft-versus-host disease (GVHD) is a primary and often lethal complication of allogenic hematopoietic stem cell transplantation (HSCT). Prophylactic regimens for GVHD are given as standard pretransplantation therapy; however, up to 50% of these patients develop acute GVHD (aGVHD) and require additional immunosuppressive intervention. Using a mouse GVHD model, we previously showed that injecting mice with exopolysaccharide (EPS) from Bacillus subtilis prior to GVHD induction significantly increased 80-day survival after transplantation of complete allogeneic major histocompatibility complex-mismatched cells. To ask whether EPS might also inhibit GVHD in humans, we used humanized NSG-HLA-A2 mice and induced GVHD by i.v. injection of A2neg human peripheral blood mononuclear cells (PBMCs). Because we could not inject human donors with EPS, we transferred EPS-pretreated dendritic cells (DCs) to inhibit aGVHD. We derived these DCs from CD34+ human cord blood cells, treated them with EPS, and then injected them together with PBMCs into the NSG-HLA-A2 mice. We found that all mice that received untreated DCs were dead by day 35, whereas 25% of mice receiving EPS-treated DCs (EPS-DCs) survived. This DC cell therapy could be readily translatable to humans, because we can generate large numbers of human EPS-DCs and use them as an "off the shelf" treatment for patients undergoing HSCT.

NKG2D receptor signaling shapes T cell thymic education.

The role of natural killer group 2D (NKG2D) in peripheral T cells as a costimulatory receptor is well established. However, its contribution to T cell thymic education and functional imprint is unknown. Here, we report significant changes in development, receptor signaling, transcriptional program, and function in T cells from mice lacking NKG2D signaling. In C57BL/6 (B6) and OT-I mice, we found that NKG2D deficiency results in Vß chain usage changes and stagnation of the double-positive stage in thymic T cell development. We found that the expression of CD5 and CD45 in thymocytes from NKG2D deficient mice were reduced, indicating a direct influence of NKG2D on the strength of T cell receptor (TCR) signaling during the developmental stage of T cells. Depicting the functional consequences of NKG2D, peripheral OT-I NKG2D-deficient cells were unresponsive to ovalbumin peptide stimulation. Paradoxically, while αCD3/CD28 agonist antibodies led to phenotypic T cell activation, their ability to produce cytokines remained severely compromised. We found that OT-I NKG2D-deficient cells activate STAT5 in response to interleukin-15 but were unable to phosphorylate ERK or S6 upon TCR engagement, underpinning a defect in TCR signaling. Finally, we showed that NKG2D is expressed in mouse and human thymic T cells at the double-negative stage, suggesting an evolutionarily conserved function during T cell development. The data presented in this study indicate that NKG2D impacts thymic T cell development at a fundamental level by reducing the TCR threshold and affecting the functional imprint of the thymic progeny. In summary, understanding the impact of NKG2D on thymic T cell development and TCR signaling contributes to our knowledge of immune system regulation, immune dysregulation, and the design of immunotherapies.