Children with autism often exhibit abnormalities in body weight,but the underlying mechanism remains unclear.SH3 and multiple ankyrin repeat domains protein 3(SHANK3),a scaffold protein of the postsynaptic density,has...Children with autism often exhibit abnormalities in body weight,but the underlying mechanism remains unclear.SH3 and multiple ankyrin repeat domains protein 3(SHANK3),a scaffold protein of the postsynaptic density,has been reported to be associated with autism.This study aimed to investigate whether and how SHANK3 influences body weight in the hypothalamic neuronal regulation of energy homeostasis.Adeno-associated viruses 9(AAV9)carrying CMV-Cre and Agrp-Cre were stereotactically injected to restore SHANK3 expression in the arcuate nucleus(ARC)and agouti-related peptide(AgRP)neurons,respectively.Agrp-Cre mice were injected with AAV9-p38αflox/flox to overexpress p38α.Activated p38αwas generated by mutating both D176A and F327S in p38α.Inactivated p38αwas constructed by mutating both T180A and Y182F in p38α.Metabolic analysis,immunoblotting,histological analysis,the glucose tolerance test,the insulin tolerance test,and body fat mass analysis were applied to investigate the underlying mechanisms by which SHANK3 regulates body weight.We reveal that SHANK3 regulates body weight via the p38αsignaling pathway in the AgRP neurons of the hypothalamus.Shank3 knockout(Shank3−/−)mice exhibit resistance to diet-induced obesity.Shank3 re-expression in the ARC or AgRP neurons increases body weight in Shank3 knock-in mice with an inverted allele(SKO).Overexpression or activation of p38αin AgRP neurons elicits resistance to diet-induced obesity.Inactivated p38αin AgRP neurons abolished the resistance to diet-induced obesity due to SHANK3 deficiency.Our findings suggest that the SHANK3-p38αsiganling pathway in AgRP neurons regulates body weight balance in autism,revealing a promising therapeutic target for obesity in children with autism.展开更多
In complex geological environments,the analysis of drill cores to determine rock strength can be challenging due to the wide variability in the degree of fracturing,leading to subjectivity in the collection of represe...In complex geological environments,the analysis of drill cores to determine rock strength can be challenging due to the wide variability in the degree of fracturing,leading to subjectivity in the collection of representative samples for uniaxial compressive strength testing.This study evaluates non-destructive techniques on calcareous rocks with different tectonic deformations,including Equotip hardness,ultrasound P-wave velocity,thin section analysis,and calcimetry,integrated with photogrammetric fracture analysis.The investigated carbonate rock samples are sourced from drill cores derived from the Umbria-Marche fold and thrust belt(northern Apennines,Italy),including a gently dipping limb of an anticline,a hinge zone of an anticline,and a fault zone associated with a thrust.Fracture intensity,quantified by the P21 parameter using photogrammetric techniques on pre-loading rock samples,is assessed alongside macroscopic identification of discontinuities(such as stylolites,veins,and joints)using marker colours to monitor failures during uniaxial compression testing.Empirical correlations depicted by single and multi-linear relationships indicate a strong dependence between the mechanical and physical properties of limestones.Both Equotip and P-wave velocity are influenced by fracture intensity,but P-wave velocity varies significantly with discontinuity orientation,especially at 45°-90°.To refine uniaxial compressive strength predictions and mitigate multicollinearity,statistical approaches,including linear and multilinear regression,Principal Component Analysis and Gaussian Process Regression,were tested.Findings improve the reliability of non-destructive techniques for assessing rock strength in structurally complex settings,with implications for geotechnical applications.展开更多
Pedicle screw is employed in several cases of spine disorders such as fractures, pseudarthrosis, spondylolisthesis, degenerative changes among others. Its essence is to fix the vertebral body in position until fusion ...Pedicle screw is employed in several cases of spine disorders such as fractures, pseudarthrosis, spondylolisthesis, degenerative changes among others. Its essence is to fix the vertebral body in position until fusion is complete. The success of this technique depends on factors like choice of size of screw for a particular pedicle size and shape. Thus, adequate knowledge of the morphometry of lumbar pedicle may avert intraoperative and postoperative complications associated with this technique, especially, neurological impairments. In this study, we determined the vertical and horizontal diameters, interpedicular distance and gender differences of 180 lumbar vertebral pedicles (140 male, 40 female pedicles) using digital vernier calipers. Results revealed a significant increase in pedicle height and width from L2 to L5. Interpedicular distance increased significantly down the vertebrae from L2 to L5. Mean vertical and horizontal diameters, interpedicular distance were not significantly different in both sexes. This study recommends a thorough check of individual’s spinal anatomy in pre-operative assessments.展开更多
BACKGROUND Carriers of chromosomal balanced translocations are often physically healthy with no obvious developmental problems.However,potential chromosomal imbalance in their gametes can lead to implantation failure,...BACKGROUND Carriers of chromosomal balanced translocations are often physically healthy with no obvious developmental problems.However,potential chromosomal imbalance in their gametes can lead to implantation failure,miscarriage,or the birth of a child with a chromosomal abnormality.CASE SUMMARY We report six cases of chromosomal translocations involving three families,including the specific Robertson(Roche)translocation.Case 1:The karyotype of the proband was 46,XX,t(18;19)(q22;p12).Case 2:Interventional prenatal diagnosis at 18 weeks of gestation confirmed that the karyotype of the fetus was 46,XY,t(18;19)(q22;p12).Case 3:The karyotype of the proband was 46,XY,t(5;18)(p13;p11).Case 4:Interventional prenatal diagnosis at 14+6 weeks confirmed that the karyotype of the fetus was 46,XX,der(18)t(5;18)(p13;p11)pat.Case 5:The karyotype of the proband was 45,XY,der(14;22)(q10;q10).Case 6:Interventional prenatal diagnosis at 19+4 weeks confirmed that the karyotype of the fetus was 45,XX,rob(14;22)(q10;q10).CONCLUSION Carriers of chromosomal translocations have a high risk of adverse pregnancy outcomes,though they can still have normal offspring.This report on six cases of chromosomal translocations from three families could serve as a reference for future prenatal diagnosis of chromosomal translocations and decision-making on whether to continue the pregnancy.展开更多
High/medium entropy alloys(H/MEAs)have shown unique strengthening behavior and mechanical prop-erties because of the presence of massive local chemical orderings.Nevertheless,dynamic interactions between chemical shor...High/medium entropy alloys(H/MEAs)have shown unique strengthening behavior and mechanical prop-erties because of the presence of massive local chemical orderings.Nevertheless,dynamic interactions between chemical short-range orders(CSROs)and dislocations,and the underlying atomic strengthening mechanism remain elusive.In this work,we first developed a novel machine learning-embedded atom method(ML-EAM)potential of the CoNiV system,trained on a comprehensive first-principles dataset,which enables accurate and efficient modeling of CSRO formation and dislocation dynamics.Then,we in-vestigated the strengthening mechanisms of CSROs in CoNiV MEA through machine learning-augmented molecular dynamics(MD)simulations.Hybrid MD/Monte Carlo simulations reveal that CSRO domains possess an L1_(2)(NiCo)_(3) V structure,whose size increases with lowering annealing temperatures.These domains significantly enhance strength by impeding dislocation motion through complex energy path-ways,increasing depinning forces,and reducing mobility.Moreover,the MD simulations combined with theoretical analysis elucidate the competition between CSRO-assisted strengthening(via antiphase bound-ary formation)and solid solution weakening(via reduced atomic misfit volume).Phonon-drag effects are also amplified by CSROs,further resisting dislocation glide.Our results demonstrate that L1_(2)-CSROs strengthen CoNiV MEA primarily through antiphase boundary and phonon-drag contributions,providing new insights for designing high-performance multi-principal-element alloys via tailoring CSROs.展开更多
BACKGROUND Prolonged immobility during intensive care unit(ICU)admission has been a cause of muscle atrophy and worsening functional outcomes with longer recovery times.Prior research has demonstrated that mobilizatio...BACKGROUND Prolonged immobility during intensive care unit(ICU)admission has been a cause of muscle atrophy and worsening functional outcomes with longer recovery times.Prior research has demonstrated that mobilization within a week of ICU admission potentially benefits physical function in critically ill patients.AIM To evaluate the effects of initiating mobilization within 72 hours of ICU admission in critically ill patients through an updated systematic review and meta-analysis.METHODS A systematic search was performed through MEDLINE,Scopus,and Cochrane Library from inception until September 2024 for randomized controlled trials(RCTs)comparing early mobilization(EM)with usual or conventional care in critically ill adult patients.Primary outcomes included length of ICU(days)and ventilation duration(days).Secondary outcomes included muscle strength,functional status,adverse events,all-cause mortality,and quality of life(QOL).A random effects meta-analysis was performed for pooled effect estimates and to derive risk ratios(RR)and corresponding 95%confidence intervals(CI).RESULTS Out of 3487 results,16 RCTs were included with a population of 2385 patients(1195 receiving EM and 1190 with usual care.)A significant reduction in the length of ICU stays[mean difference(MD)=-1.02,95%CI:-1.96 to-0.09;P=0.03;I2=60%]and ventilation duration(MD=-1.07,95%CI:-1.91 to-0.23,P=0.01;I2=57%)was observed in the EM group compared to usual care.EM significantly improved muscle strength[standard MD(SMD)=0.47,95%CI:0.18-0.75,P=0.001;I2=79%]and functional status(SMD=0.70,95%CI:0.40-1.00,P<0.00001;I2=81%)in ICU patients.No statistically significant difference was observed in adverse events(RR=1.72,95%CI:1.01-2.94,P=0.05;I2=31%),all-cause mortality(RR=1.10,95%CI:0.79-1.53,P=0.57;I2=30%),and QOL(SMD=0.04,95%CI:-0.07-0.15,P=0.50;I2=9%)between the two groups.CONCLUSION Initiating mobilization within 72 hours of ICU admission is associated with improved functional outcomes and reduced ICU length of stay and ventilation duration.These findings indicate that EM may be a safe option for ICU patients,contributing to lower recovery times and healthcare costs.Further extensive research is required to validate the long-term effects on survival and QOL.展开更多
AIM: To investigate gene variants in a large Italian inflammatory bowel disease (IBD) cohort, and to analyze the correlation of sub-phenotypes (including age at diagnosis) and epistatic interaction with other IBD gene...AIM: To investigate gene variants in a large Italian inflammatory bowel disease (IBD) cohort, and to analyze the correlation of sub-phenotypes (including age at diagnosis) and epistatic interaction with other IBD genes. METHODS: Total of 763 patients with Crohn's disease (CD, 189 diagnosed at age < 19 years), 843 with ulcerative colitis (UC, 179 diagnosed <19 years), 749 healthy controls, and 546 healthy parents (273 trios) were included in the study. The rs2241880 [autophagy-related 16-like 1 (ATG16L1)], rs11209026 and rs7517847 [interleukin 23 receptor (IL23R)], rs2066844, rs2066845, rs2066847 (CARD15), rs1050152 (OCTN1), and rs2631367 (OCTN2) gene variants were genotyped. RESULTS: The frequency of G allele of ATG16L1 SNP (Ala197Thr) was increased in patients with CD compared with controls (59% vs 54% respectively) (OR = 1.25, CI = 1.08-1.45, P = 0.003), but not in UC (55%). The frequency of A and G (minor) alleles of Arg381Gln, rs11209026 and rs7517847 variants of IL23R were reduced significantly in CD (4%, OR = 0.62, CI = 0.45-0.87, P = 0.005; 28%, OR = 0.64, CI = 0.55-0.75, P < 0.01), compared with controls (6% and 38%, respectively). The A allele (but not G) was also reduced signifi cantly in UC (4%, OR = 0.69, CI = 0.5-0.94, P = 0.019). No association was demonstrated with sub-phenotypes and interaction with CARD15 , and OCTN1/2 genes, although both gene variants were associated with pediatric-onset disease. CONCLUSION: The present study confirms the association of IL23R polymorphisms with IBD, and ATG16L1 with CD, in both adult- and pediatric-onset subsets in our study population.展开更多
Background: Numerous techniques have been proposed as “gold standard” for mastopexy, as for reduction mammaplasty. The quality of the breast parenchyma should be a primary factor in selecting the most appropriate te...Background: Numerous techniques have been proposed as “gold standard” for mastopexy, as for reduction mammaplasty. The quality of the breast parenchyma should be a primary factor in selecting the most appropriate technique for an individual case. Objective: The article describes a simple technique that can be used either for mastopexy or for reduction mammaplasty, giving optimal breast shape and position. It is appropriate for patients having some degree of ptosis, and especially for those in whom the glandular component of the breast predominates. Methods: The technique entails elevating the entire dome of the breast, rolling it under, and then stitching the two halves of the breast parenchyma together (lateral and medial dermoglandular flaps), while the upper pedicle (a third dermoglandular flap) bearing the nipple areolar complex (NAC) severed from the two inferior flaps is attached as a cap. The result is a new and attractive shape of the underlying supporting “barrel”. The technique can be performed with the T scar or the vertical scar approach. Results: The procedure was applied for various indications on 45 patients aged 20 - 62 years. Good results were only achieved in 36 women with predominant glandular component. Nine patients with fatty breasts achieved unsatisfactory results (6 with T scar, 3 with vertical scar) and very poor breast projection. Conclusions: The best-suited candidates for the proposed technique for mastopexy or reduction mammaplasty are women in whom the glandular component of the breast predominates. This simple technique, applicable with either inverted T scar or vertical scar approaches, carries very low morbidity, affording an attractive profile, long-lasting results, and conserving the patient’s ability to breast feed.展开更多
Highly pathogenic avian influenza(HPAI)H5 viruses have caused widespread mortality in wild birds and poultry,with increasing spillover risk into mammals.The recently dominant clade 2.3.4.4b has produced multiple epide...Highly pathogenic avian influenza(HPAI)H5 viruses have caused widespread mortality in wild birds and poultry,with increasing spillover risk into mammals.The recently dominant clade 2.3.4.4b has produced multiple epidemic waves,first driven by H5N8 and more recently by H5N1,which has spread more rapidly,infected a broader host range,and caused higher mortality.While earlier studies identified consistent roles of waterbird community composition in shaping HPAI outbreaks,it remains unclear whether these factors also apply to the currently circulating H5N1.We analyzed HPAI H5N1 outbreaks in European wild birds during the 2021/22epidemic,examining the influence of waterbird communities and environmental variables,and compared these patterns with earlier epidemics,including H5N1 in 2005/06 and H5N8 in 2016/17 and 2020/21.Our results showed that waterbird abundance,species richness,and the abundance of key species were positively associated with disease occurrence,whereas phylogenetic diversity was negatively associated,suggesting greater interspecific transmission among closely related hosts.Models trained on earlier epidemics accurately predicted the H5N1 occurrence in 2021/22.These findings demonstrate consistent effects of waterbird community composition across multiple epidemics and highlight their values as predictors of HPAI risk.Integrating community metrics into surveillance and early-warning systems can strengthen our capacity to anticipate future outbreaks across clades and subtypes.展开更多
Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface ...Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface waters.When released into the environment,it can accumulate over time and can lead to concentrations in soil and plant tissues that are harmful to both target and non-target organisms.As the reuse of treated wastewater and sewage sludge presents challenges and opportunities for farmers,this study investigates the effects of irrigation with environmentally relevant doses of fipronil on zucchini plants and their main insect pest,Aphis gossypii.Traces of fipronil were found in the zucchini leaves,but not in the flowers,after 35-days of cumulative exposure.A decrease in nymph-to-adult survival and a dose-dependent reduction in the fecundity of A.gossypii feeding on contaminated host plants was observed.Also,aphids feeding on contaminated host plants exhibited the same mortality rate as the control group when exposed to an acute dose of fipronil.However,when natural pyrethrins were used,there was a significant increase in resistance to this insecticide.Our results demonstrate the potential for fipronil to accumulate in plant tissues and highlight the risk of changes in insecticide susceptibility in insect pests.This suggests a need for a holistic approach to the complex dynamics of wastewater reuse in agriculture.展开更多
For the new subclass B of the bi-univalent functions constructed with the help of the(u,v)-Chebyshev polynomials of the second type,we get estimates for the first two initial coefficients and upper bounds of the Feket...For the new subclass B of the bi-univalent functions constructed with the help of the(u,v)-Chebyshev polynomials of the second type,we get estimates for the first two initial coefficients and upper bounds of the Fekete-Szeg o functional.展开更多
A series of gold-based catalysts were prepared by deposition precipitation or incipient wetness impregnation on CexZ1-xO2 solid solutions （0.28≤x≤1.00）. The morphological and structural characterization of these c...A series of gold-based catalysts were prepared by deposition precipitation or incipient wetness impregnation on CexZ1-xO2 solid solutions （0.28≤x≤1.00）. The morphological and structural characterization of these catalysts were carried out with X-ray diffraction, trans- mission electron microscopy （TEM） analysis and physical adsorption technique, and their redox properties were studied by temperature programmed reduction using both H2 and CO as probe molecules. Two cycles of oxidation/reduction were carried out in order to evaluate the effects of redox aging and gold sintering on the oxygen exchange capability. As observed with other noble metals, gold enhanced and promoted the ceria reduction at lower temperatures. Reduction by CO was shown to be dependent on the fine dispersion of gold and to be nega- tively affected by the ageing process more than reduction with hydrogen. This might have implications in reactions like water gas shift and CO-PROX which involve CO as a main reactant.展开更多
To address two key challenges(sand production and high water cut)in the development of loose sandstone reservoirs,a supramolecular sand inhibiting and water control agent,PDKM,was prepared using acrylamide(AM),methacr...To address two key challenges(sand production and high water cut)in the development of loose sandstone reservoirs,a supramolecular sand inhibiting and water control agent,PDKM,was prepared using acrylamide(AM),methacryloxyethyltrimethyl ammonium chloride(DMC),styrene(SM),and γ-methacryloyloxypropyltrimethoxysilane(KH570)as monomers.The molecular structure and thermal stability of PDKM were confirmed by ^(1)H-NMR,FT-IR,and TGA.Compared with conventional agents containing only one or two functional monomers,PDM(AM/DMC)and PDSM(AM/DMC/SM),PDKM demonstrated superior sand inhibiting and water control performance due to the synergistic effects among its three functional monomers.PDKM forms a denser intermolecular network structure,resulting in a significantly lower average sand production rate(0.02 g/L)and a longer average sand breakthrough time(665 s),surpassing the“excellent”standard(≤0.05 g/L)specified in Q/SH 10202377-2020 for sand inhibitors.PDKM achieves a higher water-oil resistance ratio(6.47)and markedly reduces the produced fluid's water cut by 34.1%,greatly exceeding the“excellent”field criterion for water control agents(≥10% reduction).Theoretical simulation(DFT calculation)reveals strong intermolecular interactions,with PDKM-PDKM and PDKM-sand grain interaction energies of−0.065 and−0.085 Ha,providing a robust theoretical basis for its performance.These findings demonstrate that PDKM offers a promising and effective solution for the integrated control of sand production and water cut in loose sandstone reservoirs.展开更多
Background:Cervical and breast cancers are among the top 4 leading causes of cancer-related mortality in women.This study aimed to examine age-specific temporal trends in mortality for cervical and breast cancers in u...Background:Cervical and breast cancers are among the top 4 leading causes of cancer-related mortality in women.This study aimed to examine age-specific temporal trends in mortality for cervical and breast cancers in urban and rural areas of China from 2009 to 2021.Methods:Age-specific mortality data for cervical and breast cancers among Chinese women aged 20-84 years were obtained from China’s National Disease Surveillance Points system spanning the years 2009 to 2021.Negative binomial regression models were utilized to assess urban-rural differences in mortality rate ratios,while Joinpoint models with estimated average annual percent changes(AAPC)and slopes were employed to compare temporal trends and the acceleration of mortality rates within different age groups.Results:From 2009 to 2021,there was a relative increase in age-specific mortality associated with the two cancers observed in rural areas compared with urban areas.A rising trend in the screening age of 35-64[AAPC:4.0%,95%confidence interval(CI)0.5-7.6,P=0.026]for cervical cancer was noted in rural areas,while a stable trend(AAPC:-0.7%,95%CI-5.8 to 4.6,P=0.780)was observed in urban areas.As for breast cancer,a stable trend(AAPC:0.3%,95%CI-0.3 to 0.9,P=0.280)was observed in rural areas compared to a decreasing trend(AAPC:-2.7%,95%CI-4.6 to-0.7,P=0.007)in urban areas.Urban-rural differences in mortality rates increased over time for cervical cancer but decreased for breast cancer.Mortality trends for both cervical and breast cancers showed an increase with age across 4 segments,with the most significant surge in mortality observed among the 35-54 age group across urban and rural areas,periods,and regions in China.Conclusions:Special attention should be given to women aged 35-54 years due to mortality trends and rural-urban disparities.Focusing on vulnerable age groups and addressing rural-urban differences in the delivery of cancer control programs can enhance resource efficiency and promote health equity.展开更多
Boron suboxide(B_(6)O)is recognized as a superhard material with a low mass density,high resistance to chemical wear,and excellent wear resistance.Despite its desirable properties,the limited fracture tough-ness of B_...Boron suboxide(B_(6)O)is recognized as a superhard material with a low mass density,high resistance to chemical wear,and excellent wear resistance.Despite its desirable properties,the limited fracture tough-ness of B_(6)O restricts its application in industrial contexts.This study presents the structural and me-chanical characterization of B_(6)O-SiC nanocomposites,which were synthesized via a high-pressure high-temperature sintering process of B_(6)O powders and SiC whiskers.The sintering process induced fragmen-tation of SiC whiskers,resulting in the homogenous distribution of SiC fragments within the B_(6)O matrix.An increase in SiC content was observed to decrease the composite’s hardness,while initially reducing then enhancing its toughness.The nanocomposites containing 20 wt%and 30 wt%SiC whiskers exhibited significant improvements in fracture toughness,averaging 6.5 MPa m^(1/2)and 7.0 MPa m^(1/2),respectively-approximately threefold the toughness of polycrystalline B_(6)O-while sustaining high hardness values of 36.3 GPa and 35.6 GPa on average.Microstructural analyses revealed that the composites’superior me-chanical performance is due to the presence of strong grain boundaries,as well as a high density of nan-otwins and stacking faults.The findings demonstrate a viable method for producing B_(6)O-based nanocom-posites with enhanced hardness and toughness,potentially expanding their industrial applicability.展开更多
The study of natural hybridization facilitates our understanding of potential adaptive mechanisms in evolution and the process involved in speciation.In this study,we used multiple data types,including morphological t...The study of natural hybridization facilitates our understanding of potential adaptive mechanisms in evolution and the process involved in speciation.In this study,we used multiple data types,including morphological traits,ddRAD-seq and ecological niche data,to investigate the differences among Rhododendron×duclouxii hybrid zones and the mechanisms underlying natural hybridization and possible future evolutionary pathways.Our results show that the origins of each hybrid zone are independent,with variations in hybrid formation,structural characteristics,and patterns of genetic components and morphological trait differentiation.There were no significant differences in morphological traits or genetic variation between the F_(1)and F_(2)generations;however,the range of variation of the F_(2)generation was broader than that of the F_(1)generation.The distribution and ecological characteristics of R.×duclouxii did not significantly differ from those of the two parental species,indicating weak ecological niche preferences between the hybrid and parental taxa.These results imply that the hybrid zones of R.×duclouxii are characterized by considerable variability,with the magnitude of hybridization in each case likely influenced by unique combinations of biological and ecological factors specific to each hybrid zone.We predict that R.×duclouxii hybrid zones will persist and give rise to complex hybrid swarms,each potentially leading to different evolutionary outcomes.展开更多
The synthesis and characterization of several dispersed molybdena catalysts on silica support (MoO3-SiO2) prepared from a variety of precursors (Mo(VI)-acetylacetonate, oxo-peroxo Mo-species, hydrated ammonium heptamo...The synthesis and characterization of several dispersed molybdena catalysts on silica support (MoO3-SiO2) prepared from a variety of precursors (Mo(VI)-acetylacetonate, oxo-peroxo Mo-species, hydrated ammonium heptamolybdate) and preparation methods (deposition of the Mo-phase on finite SiO2 support by aqueous and methanol impregnations, by adsorption, by oxo-peroxo route-like, and by one-step synthesis of MoO3-SiO2 system with molecular precursors) are presented. The molybdena concentration on silica was comprised in a large interval (1.5 - 14 wt%) depending on the preparation method which governed the Mo-loading on silica. Convenient comparisons among samples at similar Mo-concentration have been made discussing the morphologic-structural (XRD, XPS, UV-vis-DRS, and N2-adsorption) and physicochemical (TG-DTG, TPR, and n-butylamine-TPD) sample properties. Polymeric octahedral polymolybdate aggregates predominated in the samples prepared by aqueous and methanol impregnations, which were at high Mo-concentration. On the contrary, isolated Mo(VI) species in distorted Td symmetry predominated in the sample prepared by adsorption which was at very low Mo-concentration. The sample acidity was composed of a weak acidy site population, associated with the silica support, and a strong acid site population associated with the Mo-dispersed phase. Oxidation tests of formaldehyde, an oxygen-containing VOC (Volatile Organic Compound), were performed to determine the prevalent redox or acidic function of the Mo-species at the surface of the catalysts.展开更多
Biliary lithiasis is an endemic condition in both Western and Eastern countries, in some studies affecting 20% of the general population. In up to 20% of cases, gallbladder stones are associated with common bile duct ...Biliary lithiasis is an endemic condition in both Western and Eastern countries, in some studies affecting 20% of the general population. In up to 20% of cases, gallbladder stones are associated with common bile duct stones (CBDS), which are asymptomatic in up to one half of cases. Despite the wide variety of examinations and techniques available nowadays, two main open issues remain without a clear answer: how to cost-effectively diagnose CBDS and, when they are finally found, how to deal with them. CBDS diagnosis and management has radically changed over the last 30 years, following the dramatic diffusion of imaging, including endoscopic ultrasound (EUS) and magnetic resonance cholangiography (MRC), endoscopy and laparoscopy. Since accuracy, invasiveness, potential therapeutic use and cost-effectiveness of imaging techniques used to identify CBDS increase together in a parallel way, the concept of “risk of carrying CBDS” has become pivotal to identifying the most appropriate management of a specific patient in order to avoid the risk of “under-studying” by poor diagnostic work up or “over-studying” by excessively invasive examinations. The risk of carrying CBDS is deduced by symptoms, liver/pancreas serology and ultrasound. “Low risk” patients do not require further examination before laparoscopic cholecystectomy. Two main “philosophical approaches” face each other for patients with an “intermediate to high risk” of carrying CBDS: on one hand, the “laparoscopy-first” approach, which mainly relies on intraoperative cholangiography for diagnosis and laparoscopic common bile duct exploration for treatment, and, on the other hand, the “endoscopy-first” attitude, variously referring to MRC, EUS and/or endoscopic retrograde cholangiography for diagnosis and endoscopic sphincterotomy for management. Concerning CBDS diagnosis, intraoperative cholangiography, EUS and MRC are reported to have similar results. Regarding management, the recent literature seems to show better short and long term outcome of surgery in terms of retained stones and need for further procedures. Nevertheless, open surgery is invasive, whereas the laparoscopic common bile duct clearance is time consuming, technically demanding and involves dedicated instruments. Thus, although no consensus has been achieved and CBDS management seems more conditioned by the availability of instrumentation, personnel and skills than cost-effectiveness, endoscopic treatment is largely preferred worldwide.展开更多
With the rapid development of marine renewable energy technologies, the demand to mitigate the fluctuation of variable generators with energy storage technologies continues to increase. Offshore compressed air energy ...With the rapid development of marine renewable energy technologies, the demand to mitigate the fluctuation of variable generators with energy storage technologies continues to increase. Offshore compressed air energy storage (OCAES) is a novel flexible-scale energy storage technology that is suitable for marine renewable energy storage in coastal cities, islands, offshore platforms, and offshore renewable energy farms. For deep-water applications, a marine riser is necessary for connecting floating platforms and subsea systems. Thus, the response characteristics of marine risers are of great importance for the stability and safety of the entire OCAES system. In this study, numerical models of two kinds of flexible risers, namely, catenary riser and lazy wave riser, are established in OrcaFlex software. The static and dynamic characteristics of the catenary and the lazy wave risers are analyzed under different environment conditions and internal pressure levels. A sensitivity analysis of the main parameters affecting the lazy wave riser is also conducted. Results show that the structure of the lazy wave riser is more complex than the catenary riser;nevertheless, the former presents better response performance.展开更多
基金supported by the Noncommunicable Chronic Diseases-National Science and Technology Major Project(2023ZD0506800).
文摘Children with autism often exhibit abnormalities in body weight,but the underlying mechanism remains unclear.SH3 and multiple ankyrin repeat domains protein 3(SHANK3),a scaffold protein of the postsynaptic density,has been reported to be associated with autism.This study aimed to investigate whether and how SHANK3 influences body weight in the hypothalamic neuronal regulation of energy homeostasis.Adeno-associated viruses 9(AAV9)carrying CMV-Cre and Agrp-Cre were stereotactically injected to restore SHANK3 expression in the arcuate nucleus(ARC)and agouti-related peptide(AgRP)neurons,respectively.Agrp-Cre mice were injected with AAV9-p38αflox/flox to overexpress p38α.Activated p38αwas generated by mutating both D176A and F327S in p38α.Inactivated p38αwas constructed by mutating both T180A and Y182F in p38α.Metabolic analysis,immunoblotting,histological analysis,the glucose tolerance test,the insulin tolerance test,and body fat mass analysis were applied to investigate the underlying mechanisms by which SHANK3 regulates body weight.We reveal that SHANK3 regulates body weight via the p38αsignaling pathway in the AgRP neurons of the hypothalamus.Shank3 knockout(Shank3−/−)mice exhibit resistance to diet-induced obesity.Shank3 re-expression in the ARC or AgRP neurons increases body weight in Shank3 knock-in mice with an inverted allele(SKO).Overexpression or activation of p38αin AgRP neurons elicits resistance to diet-induced obesity.Inactivated p38αin AgRP neurons abolished the resistance to diet-induced obesity due to SHANK3 deficiency.Our findings suggest that the SHANK3-p38αsiganling pathway in AgRP neurons regulates body weight balance in autism,revealing a promising therapeutic target for obesity in children with autism.
文摘In complex geological environments,the analysis of drill cores to determine rock strength can be challenging due to the wide variability in the degree of fracturing,leading to subjectivity in the collection of representative samples for uniaxial compressive strength testing.This study evaluates non-destructive techniques on calcareous rocks with different tectonic deformations,including Equotip hardness,ultrasound P-wave velocity,thin section analysis,and calcimetry,integrated with photogrammetric fracture analysis.The investigated carbonate rock samples are sourced from drill cores derived from the Umbria-Marche fold and thrust belt(northern Apennines,Italy),including a gently dipping limb of an anticline,a hinge zone of an anticline,and a fault zone associated with a thrust.Fracture intensity,quantified by the P21 parameter using photogrammetric techniques on pre-loading rock samples,is assessed alongside macroscopic identification of discontinuities(such as stylolites,veins,and joints)using marker colours to monitor failures during uniaxial compression testing.Empirical correlations depicted by single and multi-linear relationships indicate a strong dependence between the mechanical and physical properties of limestones.Both Equotip and P-wave velocity are influenced by fracture intensity,but P-wave velocity varies significantly with discontinuity orientation,especially at 45°-90°.To refine uniaxial compressive strength predictions and mitigate multicollinearity,statistical approaches,including linear and multilinear regression,Principal Component Analysis and Gaussian Process Regression,were tested.Findings improve the reliability of non-destructive techniques for assessing rock strength in structurally complex settings,with implications for geotechnical applications.
文摘Pedicle screw is employed in several cases of spine disorders such as fractures, pseudarthrosis, spondylolisthesis, degenerative changes among others. Its essence is to fix the vertebral body in position until fusion is complete. The success of this technique depends on factors like choice of size of screw for a particular pedicle size and shape. Thus, adequate knowledge of the morphometry of lumbar pedicle may avert intraoperative and postoperative complications associated with this technique, especially, neurological impairments. In this study, we determined the vertical and horizontal diameters, interpedicular distance and gender differences of 180 lumbar vertebral pedicles (140 male, 40 female pedicles) using digital vernier calipers. Results revealed a significant increase in pedicle height and width from L2 to L5. Interpedicular distance increased significantly down the vertebrae from L2 to L5. Mean vertical and horizontal diameters, interpedicular distance were not significantly different in both sexes. This study recommends a thorough check of individual’s spinal anatomy in pre-operative assessments.
基金Supported by The Science and Technology Department of Jilin Province,China,No.YDZJ202301ZYTS002The Jilin Province Medical and Health Talents Project,No.2019SRCJ010.
文摘BACKGROUND Carriers of chromosomal balanced translocations are often physically healthy with no obvious developmental problems.However,potential chromosomal imbalance in their gametes can lead to implantation failure,miscarriage,or the birth of a child with a chromosomal abnormality.CASE SUMMARY We report six cases of chromosomal translocations involving three families,including the specific Robertson(Roche)translocation.Case 1:The karyotype of the proband was 46,XX,t(18;19)(q22;p12).Case 2:Interventional prenatal diagnosis at 18 weeks of gestation confirmed that the karyotype of the fetus was 46,XY,t(18;19)(q22;p12).Case 3:The karyotype of the proband was 46,XY,t(5;18)(p13;p11).Case 4:Interventional prenatal diagnosis at 14+6 weeks confirmed that the karyotype of the fetus was 46,XX,der(18)t(5;18)(p13;p11)pat.Case 5:The karyotype of the proband was 45,XY,der(14;22)(q10;q10).Case 6:Interventional prenatal diagnosis at 19+4 weeks confirmed that the karyotype of the fetus was 45,XX,rob(14;22)(q10;q10).CONCLUSION Carriers of chromosomal translocations have a high risk of adverse pregnancy outcomes,though they can still have normal offspring.This report on six cases of chromosomal translocations from three families could serve as a reference for future prenatal diagnosis of chromosomal translocations and decision-making on whether to continue the pregnancy.
基金financially supported by the National Natural Science Foundation of China(Nos.52071024,52271003 and 52101188)the National Science Fund for Distinguished Young Scholars of China(No.52225103)+2 种基金the Funds for Creative Research Groups of China(No.51921001)the Projects of International Cooperation and Exchanges NSFC(Nos.51961160729 and 52061135207)the Fundamental Research Fund for the Central Universities of China,and the State Key Laboratory for Advanced Metals and Materials.
文摘High/medium entropy alloys(H/MEAs)have shown unique strengthening behavior and mechanical prop-erties because of the presence of massive local chemical orderings.Nevertheless,dynamic interactions between chemical short-range orders(CSROs)and dislocations,and the underlying atomic strengthening mechanism remain elusive.In this work,we first developed a novel machine learning-embedded atom method(ML-EAM)potential of the CoNiV system,trained on a comprehensive first-principles dataset,which enables accurate and efficient modeling of CSRO formation and dislocation dynamics.Then,we in-vestigated the strengthening mechanisms of CSROs in CoNiV MEA through machine learning-augmented molecular dynamics(MD)simulations.Hybrid MD/Monte Carlo simulations reveal that CSRO domains possess an L1_(2)(NiCo)_(3) V structure,whose size increases with lowering annealing temperatures.These domains significantly enhance strength by impeding dislocation motion through complex energy path-ways,increasing depinning forces,and reducing mobility.Moreover,the MD simulations combined with theoretical analysis elucidate the competition between CSRO-assisted strengthening(via antiphase bound-ary formation)and solid solution weakening(via reduced atomic misfit volume).Phonon-drag effects are also amplified by CSROs,further resisting dislocation glide.Our results demonstrate that L1_(2)-CSROs strengthen CoNiV MEA primarily through antiphase boundary and phonon-drag contributions,providing new insights for designing high-performance multi-principal-element alloys via tailoring CSROs.
文摘BACKGROUND Prolonged immobility during intensive care unit(ICU)admission has been a cause of muscle atrophy and worsening functional outcomes with longer recovery times.Prior research has demonstrated that mobilization within a week of ICU admission potentially benefits physical function in critically ill patients.AIM To evaluate the effects of initiating mobilization within 72 hours of ICU admission in critically ill patients through an updated systematic review and meta-analysis.METHODS A systematic search was performed through MEDLINE,Scopus,and Cochrane Library from inception until September 2024 for randomized controlled trials(RCTs)comparing early mobilization(EM)with usual or conventional care in critically ill adult patients.Primary outcomes included length of ICU(days)and ventilation duration(days).Secondary outcomes included muscle strength,functional status,adverse events,all-cause mortality,and quality of life(QOL).A random effects meta-analysis was performed for pooled effect estimates and to derive risk ratios(RR)and corresponding 95%confidence intervals(CI).RESULTS Out of 3487 results,16 RCTs were included with a population of 2385 patients(1195 receiving EM and 1190 with usual care.)A significant reduction in the length of ICU stays[mean difference(MD)=-1.02,95%CI:-1.96 to-0.09;P=0.03;I2=60%]and ventilation duration(MD=-1.07,95%CI:-1.91 to-0.23,P=0.01;I2=57%)was observed in the EM group compared to usual care.EM significantly improved muscle strength[standard MD(SMD)=0.47,95%CI:0.18-0.75,P=0.001;I2=79%]and functional status(SMD=0.70,95%CI:0.40-1.00,P<0.00001;I2=81%)in ICU patients.No statistically significant difference was observed in adverse events(RR=1.72,95%CI:1.01-2.94,P=0.05;I2=31%),all-cause mortality(RR=1.10,95%CI:0.79-1.53,P=0.57;I2=30%),and QOL(SMD=0.04,95%CI:-0.07-0.15,P=0.50;I2=9%)between the two groups.CONCLUSION Initiating mobilization within 72 hours of ICU admission is associated with improved functional outcomes and reduced ICU length of stay and ventilation duration.These findings indicate that EM may be a safe option for ICU patients,contributing to lower recovery times and healthcare costs.Further extensive research is required to validate the long-term effects on survival and QOL.
基金The National Minister of Health grant, No. RC0702GA35
文摘AIM: To investigate gene variants in a large Italian inflammatory bowel disease (IBD) cohort, and to analyze the correlation of sub-phenotypes (including age at diagnosis) and epistatic interaction with other IBD genes. METHODS: Total of 763 patients with Crohn's disease (CD, 189 diagnosed at age < 19 years), 843 with ulcerative colitis (UC, 179 diagnosed <19 years), 749 healthy controls, and 546 healthy parents (273 trios) were included in the study. The rs2241880 [autophagy-related 16-like 1 (ATG16L1)], rs11209026 and rs7517847 [interleukin 23 receptor (IL23R)], rs2066844, rs2066845, rs2066847 (CARD15), rs1050152 (OCTN1), and rs2631367 (OCTN2) gene variants were genotyped. RESULTS: The frequency of G allele of ATG16L1 SNP (Ala197Thr) was increased in patients with CD compared with controls (59% vs 54% respectively) (OR = 1.25, CI = 1.08-1.45, P = 0.003), but not in UC (55%). The frequency of A and G (minor) alleles of Arg381Gln, rs11209026 and rs7517847 variants of IL23R were reduced significantly in CD (4%, OR = 0.62, CI = 0.45-0.87, P = 0.005; 28%, OR = 0.64, CI = 0.55-0.75, P < 0.01), compared with controls (6% and 38%, respectively). The A allele (but not G) was also reduced signifi cantly in UC (4%, OR = 0.69, CI = 0.5-0.94, P = 0.019). No association was demonstrated with sub-phenotypes and interaction with CARD15 , and OCTN1/2 genes, although both gene variants were associated with pediatric-onset disease. CONCLUSION: The present study confirms the association of IL23R polymorphisms with IBD, and ATG16L1 with CD, in both adult- and pediatric-onset subsets in our study population.
文摘Background: Numerous techniques have been proposed as “gold standard” for mastopexy, as for reduction mammaplasty. The quality of the breast parenchyma should be a primary factor in selecting the most appropriate technique for an individual case. Objective: The article describes a simple technique that can be used either for mastopexy or for reduction mammaplasty, giving optimal breast shape and position. It is appropriate for patients having some degree of ptosis, and especially for those in whom the glandular component of the breast predominates. Methods: The technique entails elevating the entire dome of the breast, rolling it under, and then stitching the two halves of the breast parenchyma together (lateral and medial dermoglandular flaps), while the upper pedicle (a third dermoglandular flap) bearing the nipple areolar complex (NAC) severed from the two inferior flaps is attached as a cap. The result is a new and attractive shape of the underlying supporting “barrel”. The technique can be performed with the T scar or the vertical scar approach. Results: The procedure was applied for various indications on 45 patients aged 20 - 62 years. Good results were only achieved in 36 women with predominant glandular component. Nine patients with fatty breasts achieved unsatisfactory results (6 with T scar, 3 with vertical scar) and very poor breast projection. Conclusions: The best-suited candidates for the proposed technique for mastopexy or reduction mammaplasty are women in whom the glandular component of the breast predominates. This simple technique, applicable with either inverted T scar or vertical scar approaches, carries very low morbidity, affording an attractive profile, long-lasting results, and conserving the patient’s ability to breast feed.
基金supported by the National Natural Science Foundation of China(32271605)。
文摘Highly pathogenic avian influenza(HPAI)H5 viruses have caused widespread mortality in wild birds and poultry,with increasing spillover risk into mammals.The recently dominant clade 2.3.4.4b has produced multiple epidemic waves,first driven by H5N8 and more recently by H5N1,which has spread more rapidly,infected a broader host range,and caused higher mortality.While earlier studies identified consistent roles of waterbird community composition in shaping HPAI outbreaks,it remains unclear whether these factors also apply to the currently circulating H5N1.We analyzed HPAI H5N1 outbreaks in European wild birds during the 2021/22epidemic,examining the influence of waterbird communities and environmental variables,and compared these patterns with earlier epidemics,including H5N1 in 2005/06 and H5N8 in 2016/17 and 2020/21.Our results showed that waterbird abundance,species richness,and the abundance of key species were positively associated with disease occurrence,whereas phylogenetic diversity was negatively associated,suggesting greater interspecific transmission among closely related hosts.Models trained on earlier epidemics accurately predicted the H5N1 occurrence in 2021/22.These findings demonstrate consistent effects of waterbird community composition across multiple epidemics and highlight their values as predictors of HPAI risk.Integrating community metrics into surveillance and early-warning systems can strengthen our capacity to anticipate future outbreaks across clades and subtypes.
基金funding from MUR under the umbrella of the PRIMA-Partnership for Research&Innovation in the Mediterranean Area through the research project SAFE"Sustainable water reuse practices improving safety in agriculture,food and environment"support from the CERCA Institute through the CERCAGINYS programme,funded by the Spanish Ministry of Science and Innovationsupport from the Economy and Knowledge Department of the Catalan Government through a Consolidated Research Groups(ICRA-ENV-2021 SGR 01282 and ICRA-TECH 2021 SGR 01283)。
文摘Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface waters.When released into the environment,it can accumulate over time and can lead to concentrations in soil and plant tissues that are harmful to both target and non-target organisms.As the reuse of treated wastewater and sewage sludge presents challenges and opportunities for farmers,this study investigates the effects of irrigation with environmentally relevant doses of fipronil on zucchini plants and their main insect pest,Aphis gossypii.Traces of fipronil were found in the zucchini leaves,but not in the flowers,after 35-days of cumulative exposure.A decrease in nymph-to-adult survival and a dose-dependent reduction in the fecundity of A.gossypii feeding on contaminated host plants was observed.Also,aphids feeding on contaminated host plants exhibited the same mortality rate as the control group when exposed to an acute dose of fipronil.However,when natural pyrethrins were used,there was a significant increase in resistance to this insecticide.Our results demonstrate the potential for fipronil to accumulate in plant tissues and highlight the risk of changes in insecticide susceptibility in insect pests.This suggests a need for a holistic approach to the complex dynamics of wastewater reuse in agriculture.
文摘For the new subclass B of the bi-univalent functions constructed with the help of the(u,v)-Chebyshev polynomials of the second type,we get estimates for the first two initial coefficients and upper bounds of the Fekete-Szeg o functional.
文摘A series of gold-based catalysts were prepared by deposition precipitation or incipient wetness impregnation on CexZ1-xO2 solid solutions （0.28≤x≤1.00）. The morphological and structural characterization of these catalysts were carried out with X-ray diffraction, trans- mission electron microscopy （TEM） analysis and physical adsorption technique, and their redox properties were studied by temperature programmed reduction using both H2 and CO as probe molecules. Two cycles of oxidation/reduction were carried out in order to evaluate the effects of redox aging and gold sintering on the oxygen exchange capability. As observed with other noble metals, gold enhanced and promoted the ceria reduction at lower temperatures. Reduction by CO was shown to be dependent on the fine dispersion of gold and to be nega- tively affected by the ageing process more than reduction with hydrogen. This might have implications in reactions like water gas shift and CO-PROX which involve CO as a main reactant.
基金supported by the National Natural Science Foundation of China(General Program,Grant No.52474071)the Provincial Key R&D Program of Shandong(2022CXGC020303)support from the China Scholarship Council(T.-M.Lei,No.202406450004).
文摘To address two key challenges(sand production and high water cut)in the development of loose sandstone reservoirs,a supramolecular sand inhibiting and water control agent,PDKM,was prepared using acrylamide(AM),methacryloxyethyltrimethyl ammonium chloride(DMC),styrene(SM),and γ-methacryloyloxypropyltrimethoxysilane(KH570)as monomers.The molecular structure and thermal stability of PDKM were confirmed by ^(1)H-NMR,FT-IR,and TGA.Compared with conventional agents containing only one or two functional monomers,PDM(AM/DMC)and PDSM(AM/DMC/SM),PDKM demonstrated superior sand inhibiting and water control performance due to the synergistic effects among its three functional monomers.PDKM forms a denser intermolecular network structure,resulting in a significantly lower average sand production rate(0.02 g/L)and a longer average sand breakthrough time(665 s),surpassing the“excellent”standard(≤0.05 g/L)specified in Q/SH 10202377-2020 for sand inhibitors.PDKM achieves a higher water-oil resistance ratio(6.47)and markedly reduces the produced fluid's water cut by 34.1%,greatly exceeding the“excellent”field criterion for water control agents(≥10% reduction).Theoretical simulation(DFT calculation)reveals strong intermolecular interactions,with PDKM-PDKM and PDKM-sand grain interaction energies of−0.065 and−0.085 Ha,providing a robust theoretical basis for its performance.These findings demonstrate that PDKM offers a promising and effective solution for the integrated control of sand production and water cut in loose sandstone reservoirs.
基金supported by the High-Level Public Health Specialized Talents Project of Beijing Municipal Health Commission(YFH,2024-3-028)the National Natural Science Foundation of China(YFH,72061137007)SHV is supported,in part,by U.S.National Institutes of Health(P30CA016359).
文摘Background:Cervical and breast cancers are among the top 4 leading causes of cancer-related mortality in women.This study aimed to examine age-specific temporal trends in mortality for cervical and breast cancers in urban and rural areas of China from 2009 to 2021.Methods:Age-specific mortality data for cervical and breast cancers among Chinese women aged 20-84 years were obtained from China’s National Disease Surveillance Points system spanning the years 2009 to 2021.Negative binomial regression models were utilized to assess urban-rural differences in mortality rate ratios,while Joinpoint models with estimated average annual percent changes(AAPC)and slopes were employed to compare temporal trends and the acceleration of mortality rates within different age groups.Results:From 2009 to 2021,there was a relative increase in age-specific mortality associated with the two cancers observed in rural areas compared with urban areas.A rising trend in the screening age of 35-64[AAPC:4.0%,95%confidence interval(CI)0.5-7.6,P=0.026]for cervical cancer was noted in rural areas,while a stable trend(AAPC:-0.7%,95%CI-5.8 to 4.6,P=0.780)was observed in urban areas.As for breast cancer,a stable trend(AAPC:0.3%,95%CI-0.3 to 0.9,P=0.280)was observed in rural areas compared to a decreasing trend(AAPC:-2.7%,95%CI-4.6 to-0.7,P=0.007)in urban areas.Urban-rural differences in mortality rates increased over time for cervical cancer but decreased for breast cancer.Mortality trends for both cervical and breast cancers showed an increase with age across 4 segments,with the most significant surge in mortality observed among the 35-54 age group across urban and rural areas,periods,and regions in China.Conclusions:Special attention should be given to women aged 35-54 years due to mortality trends and rural-urban disparities.Focusing on vulnerable age groups and addressing rural-urban differences in the delivery of cancer control programs can enhance resource efficiency and promote health equity.
基金supported by the Natural Science Foundation of Hebei Province of China(E2022203109)the National Natural Sci-ence Foundation of China(Grant No.52202049,52103322)+5 种基金the Natural Science Foundation of Jiangxi Province of China(Grant No.20202BAB214010)the Open Funds of the State Key Laboratory of Metastable Materials Science and Technology(Grant No.201906)Ganzhou Science and Technology Project(Grant No.202060)the Program of Qingjiang Excellent Young Talents,Jiangxi Univer-sity of Science and Technology(JXUSTQJYX2020002)China Post-doctoral Science Foundation(2023M731866)the Macao Young Scholars Program(AM2021015).
文摘Boron suboxide(B_(6)O)is recognized as a superhard material with a low mass density,high resistance to chemical wear,and excellent wear resistance.Despite its desirable properties,the limited fracture tough-ness of B_(6)O restricts its application in industrial contexts.This study presents the structural and me-chanical characterization of B_(6)O-SiC nanocomposites,which were synthesized via a high-pressure high-temperature sintering process of B_(6)O powders and SiC whiskers.The sintering process induced fragmen-tation of SiC whiskers,resulting in the homogenous distribution of SiC fragments within the B_(6)O matrix.An increase in SiC content was observed to decrease the composite’s hardness,while initially reducing then enhancing its toughness.The nanocomposites containing 20 wt%and 30 wt%SiC whiskers exhibited significant improvements in fracture toughness,averaging 6.5 MPa m^(1/2)and 7.0 MPa m^(1/2),respectively-approximately threefold the toughness of polycrystalline B_(6)O-while sustaining high hardness values of 36.3 GPa and 35.6 GPa on average.Microstructural analyses revealed that the composites’superior me-chanical performance is due to the presence of strong grain boundaries,as well as a high density of nan-otwins and stacking faults.The findings demonstrate a viable method for producing B_(6)O-based nanocom-posites with enhanced hardness and toughness,potentially expanding their industrial applicability.
基金supported by the National Natural Science Foundation of China,China(32300200,31670213,32160240)Postdoctoral Directional Training Foundation of Yunnan Province,China(E33O31C261)+2 种基金the Key Basic Research Program of Yunnan Province,China(202101BC070003)the CAS President’s International Fellowship Initiative,China(2024PVA0087)supported by the Rural and Environment Science and Analytical Services Division of the Scottish Government,United Kingdom.
文摘The study of natural hybridization facilitates our understanding of potential adaptive mechanisms in evolution and the process involved in speciation.In this study,we used multiple data types,including morphological traits,ddRAD-seq and ecological niche data,to investigate the differences among Rhododendron×duclouxii hybrid zones and the mechanisms underlying natural hybridization and possible future evolutionary pathways.Our results show that the origins of each hybrid zone are independent,with variations in hybrid formation,structural characteristics,and patterns of genetic components and morphological trait differentiation.There were no significant differences in morphological traits or genetic variation between the F_(1)and F_(2)generations;however,the range of variation of the F_(2)generation was broader than that of the F_(1)generation.The distribution and ecological characteristics of R.×duclouxii did not significantly differ from those of the two parental species,indicating weak ecological niche preferences between the hybrid and parental taxa.These results imply that the hybrid zones of R.×duclouxii are characterized by considerable variability,with the magnitude of hybridization in each case likely influenced by unique combinations of biological and ecological factors specific to each hybrid zone.We predict that R.×duclouxii hybrid zones will persist and give rise to complex hybrid swarms,each potentially leading to different evolutionary outcomes.
文摘The synthesis and characterization of several dispersed molybdena catalysts on silica support (MoO3-SiO2) prepared from a variety of precursors (Mo(VI)-acetylacetonate, oxo-peroxo Mo-species, hydrated ammonium heptamolybdate) and preparation methods (deposition of the Mo-phase on finite SiO2 support by aqueous and methanol impregnations, by adsorption, by oxo-peroxo route-like, and by one-step synthesis of MoO3-SiO2 system with molecular precursors) are presented. The molybdena concentration on silica was comprised in a large interval (1.5 - 14 wt%) depending on the preparation method which governed the Mo-loading on silica. Convenient comparisons among samples at similar Mo-concentration have been made discussing the morphologic-structural (XRD, XPS, UV-vis-DRS, and N2-adsorption) and physicochemical (TG-DTG, TPR, and n-butylamine-TPD) sample properties. Polymeric octahedral polymolybdate aggregates predominated in the samples prepared by aqueous and methanol impregnations, which were at high Mo-concentration. On the contrary, isolated Mo(VI) species in distorted Td symmetry predominated in the sample prepared by adsorption which was at very low Mo-concentration. The sample acidity was composed of a weak acidy site population, associated with the silica support, and a strong acid site population associated with the Mo-dispersed phase. Oxidation tests of formaldehyde, an oxygen-containing VOC (Volatile Organic Compound), were performed to determine the prevalent redox or acidic function of the Mo-species at the surface of the catalysts.
文摘Biliary lithiasis is an endemic condition in both Western and Eastern countries, in some studies affecting 20% of the general population. In up to 20% of cases, gallbladder stones are associated with common bile duct stones (CBDS), which are asymptomatic in up to one half of cases. Despite the wide variety of examinations and techniques available nowadays, two main open issues remain without a clear answer: how to cost-effectively diagnose CBDS and, when they are finally found, how to deal with them. CBDS diagnosis and management has radically changed over the last 30 years, following the dramatic diffusion of imaging, including endoscopic ultrasound (EUS) and magnetic resonance cholangiography (MRC), endoscopy and laparoscopy. Since accuracy, invasiveness, potential therapeutic use and cost-effectiveness of imaging techniques used to identify CBDS increase together in a parallel way, the concept of “risk of carrying CBDS” has become pivotal to identifying the most appropriate management of a specific patient in order to avoid the risk of “under-studying” by poor diagnostic work up or “over-studying” by excessively invasive examinations. The risk of carrying CBDS is deduced by symptoms, liver/pancreas serology and ultrasound. “Low risk” patients do not require further examination before laparoscopic cholecystectomy. Two main “philosophical approaches” face each other for patients with an “intermediate to high risk” of carrying CBDS: on one hand, the “laparoscopy-first” approach, which mainly relies on intraoperative cholangiography for diagnosis and laparoscopic common bile duct exploration for treatment, and, on the other hand, the “endoscopy-first” attitude, variously referring to MRC, EUS and/or endoscopic retrograde cholangiography for diagnosis and endoscopic sphincterotomy for management. Concerning CBDS diagnosis, intraoperative cholangiography, EUS and MRC are reported to have similar results. Regarding management, the recent literature seems to show better short and long term outcome of surgery in terms of retained stones and need for further procedures. Nevertheless, open surgery is invasive, whereas the laparoscopic common bile duct clearance is time consuming, technically demanding and involves dedicated instruments. Thus, although no consensus has been achieved and CBDS management seems more conditioned by the availability of instrumentation, personnel and skills than cost-effectiveness, endoscopic treatment is largely preferred worldwide.
基金supported by the Fundamental Research Funds for the Central Universities of China(grant numbers 3132016353,3132019117,3132019122)the Natural Sciences and Engineering Research Council of Canada
文摘With the rapid development of marine renewable energy technologies, the demand to mitigate the fluctuation of variable generators with energy storage technologies continues to increase. Offshore compressed air energy storage (OCAES) is a novel flexible-scale energy storage technology that is suitable for marine renewable energy storage in coastal cities, islands, offshore platforms, and offshore renewable energy farms. For deep-water applications, a marine riser is necessary for connecting floating platforms and subsea systems. Thus, the response characteristics of marine risers are of great importance for the stability and safety of the entire OCAES system. In this study, numerical models of two kinds of flexible risers, namely, catenary riser and lazy wave riser, are established in OrcaFlex software. The static and dynamic characteristics of the catenary and the lazy wave risers are analyzed under different environment conditions and internal pressure levels. A sensitivity analysis of the main parameters affecting the lazy wave riser is also conducted. Results show that the structure of the lazy wave riser is more complex than the catenary riser;nevertheless, the former presents better response performance.
