The manipulation of photon blockade via Newtonian gravity.

We theoretically investigate the model of a quadratically coupled optomechanical system with a Newtonian gravitational potential in the weak-driving regime, where the optical cavity is driven by an external laser. The steady state of the whole system is treated in the framework of a few-photon subspace. We find that the conventional single-photon blockade, nonstandard types of single-photon blockade, two-photon blockade, and photon-induced tunneling can be induced by gravity when the quadratic optomechanical coupling strength remains constant. Moreover, we find that gravitational potential energy can compensate for the lack of quadratic optomechanical coupling for observation photon blockade. In particular, the photon stream with super-Poissonian distribution can be converted into a sub-Poissonian, antibunching photon stream by changing the driving detuning when the gravitational potential energy is included. These results show that the gravity has potential for realizing the manipulation of photon blockade in a quadratically coupled optomechanical system.

Aggregation induced emission dynamic chiral europium(III) complexes with excellent circularly polarized luminescence and smart sensors.

The synthesis of dynamic chiral lanthanide complex emitters has always been difficult. Herein, we report three pairs of dynamic chiral EuIII complex emitters (R/S-Eu-R-1, R = Et/Me; R/S-Eu-Et-2) with aggregation-induced emission. In the molecular state, these EuIII complexes have almost no obvious emission, while in the aggregate state, they greatly enhance the EuIII emission through restriction of intramolecular rotation and restriction of intramolecular vibration. The asymmetry factor and the circularly polarized luminescence brightness are as high as 0.64 (5D0 → 7F1) and 2429 M-1cm-1 of R-Eu-Et-1, achieving a rare double improvement. R-Eu-Et-1/2 exhibit excellent sensing properties for low concentrations of CuII ions, and their detection limits are as low as 2.55 and 4.44 nM, respectively. Dynamic EuIII complexes are constructed by using chiral ligands with rotor structures or vibration units, an approach that opens a door for the construction of dynamic chiral luminescent materials.

Different anion (NO3- and OAc-)-controlled construction of dysprosium clusters with different shapes.

The complex hydrolysis process and strong uncertainty of self-assembly rules have led to the precise synthesis of lanthanide clusters still being in the "blind-box" stage and simplifying the self-assembly process and developing reliable regulation strategies have attracted widespread attention. Herein, different anions are used to induce the construction of a series of dysprosium clusters with different shapes and connections. When the selected anion is NO3-, it blocks the coordination of metal sites around the cluster through the terminal group coordination mode, thereby controlling the growth of the cluster. When NO3- was changed to OAc-, OAc- adopted a bridging mode to induce modular units to build dysprosium clusters through an annular growth mechanism. Specifically, we selected 2-amino-6-methoxybenzoic acid, 2-hydroxybenzaldehyde, and Dy(NO3)3·6H2O to react under solvothermal conditions to obtain a pentanuclear dysprosium cluster (1). The five Dy(III) ions in 1 are distributed in upper and lower planes and are formed by the tight connection of nitrogen and oxygen atoms, and µ3-OH- bridges on the ligand. Next, octa-nuclear dysprosium cluster (2) were obtained by only regulating ligand substituents. The eight Dy(III) ions in 2 are tightly connected through ligand oxygen atoms, µ2-OH-, and µ3-OH- bridges, forming an elliptical {Dy/O} cluster core. Furthermore, only by changing NO3- to OAc-, a wheel-shaped tetradeca-nuclear dysprosium cluster (3) was obtained. Cluster 3 is composed of OAc- bridged multiple template Dy3L3 units and pulling of these template units connected by an annular growth mechanism forms a wheel-shaped cluster. The angle of the coordination site on NO3- is ∠ONO = 115°, which leads to the further extension of the metal sites on the periphery of clusters 1 and 2 through the terminal group coordination mode, thereby regulating the structural connection of the clusters. However, the angle of the coordination site on OAc- is ∠OCO = 128°, and a slightly increased angle leads to the formation of a ring-shaped cluster 3 by connecting the template units through bridging. This is a rare example of the controllable construction of lanthanide clusters with different shapes induced by the regulation of different anions, which provides a new method for the precise construction of lanthanide clusters with special shapes.

Aggregation-Induced Emission via the Restriction of the Intramolecular Vibration Mechanism of Pinacol Lanthanide Complexes.

Pinacol lanthanide complexes PyraLn (Ln = Dy and Tb) with the restriction of intramolecular vibration were obtained for the first time via an in situ solvothermal coordination-catalyzed tandem reaction using cheap and simple starting materials, thereby avoiding complex, time-consuming, and expensive conventional organic synthesis strategies. A high-resolution electrospray ionization mass spectrometry (HRESI-MS) analysis confirmed the stability of PyraLn in an organic solution. The formation process of PyraLn was monitored in detail using time-dependent HRESI-MS, which allowed for proposing a mechanism for the formation of pinacol complexes via in situ tandem reactions under one-pot coordination-catalyzed conditions. The PyraLn complexes constructed using a pinacol ligand with a butterfly configuration exhibited distinct aggregation-induced emission (AIE) behavior, with the αAIE value as high as 60.42 according to the AIE titration curve. In addition, the PyraLn complexes in the aggregated state exhibit a rapid photoresponse to various 3d metal ions with low detection limits. These findings provide fast, facile, and high-yield access to dynamic, smart lanthanide complex emissions with bright emission and facilitate the rational construction of molecular machines for artificial intelligence.

Prevalence and risk factors of frailty in older patients with chronic heart failure: a systematic review and meta-analysis.

AIM: To provide a summary of the available evidence concerning prevalence and risk factors of frailty in elderly patients with CHF. METHODS: PubMed, Embase, Web of Science, CINAHL, The Cochrane Library, China National Knowledge Infrastructure Database (CNKI), Chinese Biomedical Database (Sinomed), Weipu Database (VIP), and Wanfang database were searched from inception to July 2023. This study strictly followed the PRISMA guidelines. The quality of the included studies was rated by the Agency for Healthcare and Research and Quality and the Newcastle-Ottawa Scale. RESULTS: A total of 21 original studies were included, involving 4,797 patients. Meta-analysis results showed that the prevalence of frailty in older patients with heart failure was 38% (95%CI: 0.32-0.44). Age, cardiac function grading, left atrial diameter, left ventricular ejection fraction, hemoglobin, polypharmacy, BNP, nutritional risk, and hospitalization day are the influential factors of frailty in older patients with CHF. CONCLUSION: The prevalence of frailty in older patients with CHF is high, and clinical medical personnel should identify and intervene early to reduce or delay the frailty in older patients with CHF as much as possible.

Association Analysis of Tiller-Related Traits with EST-SSR Markers in Psathyrostachys juncea.

Psathyrostachys juncea is a long-lived perennial Gramineae grass with dense basal tillers and soft leaves. It is used widely in cold and dry areas of Eurasia and North America to establish grazing pasture and is even used as an ideal plant for revegetation and ecological restoration. Plant architecture, especially tillering traits, is critical for bunch grasses in breeding programs, and these traits in plants are mostly quantitative traits. In this study, the genetic diversity, population structure, and linkage disequilibrium of 480 individual lines were analyzed using 127 pairs of the EST-SSR marker, and a significant association between ten plant-architecture-related traits of P. juncea and molecular markers was found. The results of the genetic diversity analysis showed that the number of observed alleles was 1.957, the number of effective alleles was 1.682, Shannon's information index was 0.554, observed heterozygosity was 0.353, expected heterozygosity was 0.379, and the polymorphism information content was 0.300. A total of 480 individual lines were clustered into five groups based on population genetic structure, principal coordinate analysis, and unweighted pair group method with arithmetic mean analysis (UPGMA). The linkage disequilibrium coefficient (r2) was between 0.00 and 0.68, with an average of 0.04, which indicated a relatively low level of linkage disequilibrium among loci. The results of the association analysis revealed 55 significant marker-trait associations (MTA). Moreover, nine SSR markers were associated with multiple traits. This study provides tools with promising applications in the molecular selection and breeding of P. juncea germplasm.

Prevalence and risk factors for colonisation and infection with carbapenem-resistant Enterobacterales in intensive care units: A prospective multicentre study.

OBJECTIVES: This study aimed to investigate the prevalence and risk factors for carbapenem-resistant Enterobacterales colonisation/infection at admission and acquisition among patients admitted to the intensive care unit. RESEARCH METHODOLOGY/DESIGN: A prospective and multicentre study. SETTING: This study was conducted in 24 intensive care units in Anhui, China. MAIN OUTCOME MEASURES: Demographic and clinical data were collected, and rectal carbapenem-resistant Enterobacterales colonisation was detected by active screening. Multivariate logistic regression models were used to analyse factors associated with colonisation/infection with carbapenem-resistant Enterobacterales at admission and acquisition during the intensive care unit stay. RESULTS: There were 1133 intensive care unit patients included in this study. In total, 5.9% of patients with carbapenem-resistant Enterobacterales colonisation/infection at admission, and of which 56.7% were colonisations. Besides, 8.5% of patients acquired carbapenem-resistant Enterobacterales colonisation/infection during the intensive care stay, and of which 67.6% were colonisations. At admission, transfer from another hospital, admission to an intensive care unit within one year, colonisation/infection/epidemiological link with carbapenem-resistant Enterobacterales within one year, and exposure to any antibiotics within three months were risk factors for colonisation/infection with carbapenem-resistant Enterobacterales. During the intensive care stay, renal disease, an epidemiological link with carbapenem-resistant Enterobacterales, exposure to carbapenems and beta-lactams/beta-lactamase inhibitors, and intensive care stay of three weeks or longer were associated with acquisition. CONCLUSION: The prevalence of colonisation/infection with carbapenem-resistant Enterobacterales in intensive care units is of great concern and should be monitored systematically. Particularly for the 8.5% prevalence of carbapenem-resistant Enterobacterales acquisition during the intensive care stay needs enhanced infection prevention and control measures in these setting. Surveillance of colonisation/infection with carbapenem-resistant Enterobacterales at admission and during the patient's stay represents an early identification tool to prevent further transmission of carbapenem-resistant Enterobacterales. IMPLICATIONS FOR CLINICAL PRACTICE: Carbapenem-resistant Enterobacterales colonization screening at admission and during the patient's stay is an important tool to control carbapenem-resistant Enterobacterales spread in intensive care units.

Detection of Epstein-Barr virus infection in thymic epithelial tumors by nested PCR and Epstein-Barr-encoded RNA ISH.

BACKGROUND: Epstein-Barr virus (EBV) is well known to be associated with a lot of tumors, including lymphoma, nasopharyngeal carcinoma, EBV-associated gastric carcinoma, and some other carcinomas with similar lymphoepithelioma-like features. However, the association between EBV and thymic epithelial tumors (TETs) is inconclusive as reports in this regard are not entirely consistent and the methods employed are of different sensitivity and specificity. The geographical difference of the patients is also one of the reasons for the different points of view. METHODS: In our study, we examined 72 thymomas, including 3 cases of type A thymomas, 27 cases of type AB, 6 cases of type B1, 26 cases of type B2 and 10 cases of type B3 thymomas, and 15 thymic carcinomas to detect the viral genome at both DNA and RNA levels. The genome DNA of fresh tissues was first screened by nested polymerase chain reaction (PCR), which could be regarded as the most sensitive method to detect small amounts of DNA. Then all the tissue blocks were further submitted for viral localization by Epstein-Barr-encoded RNA (EBER) ISH. Group parameters were assessed using the chi-square test at a significance level of p < 0.05. RESULTS: Nested PCR results showed that none of type A, eight (29.6%) type AB, one (16.7%) type B1, fifteen (57.7%) type B2, and four (40.0%) type B3 were positive for EBV genome. However, none of them detected EBER expression except for one case of type B2 thymoma. Fourteen (93.3%) thymic carcinomas were positive for EBV by nested PCR, of which three displayed weak nuclear signals within the tumor cells by EBER ISH. CONCLUSIONS: These results showed that nested PCR was a sensitive method for screening the EBV genome in thymic epithelial tumors. As the malignancy of thymoma increases, the rate of EBV infection became higher. Thymic carcinomas were well associated with the Epstein-Barr virus.There was significant association between the EBV infection rate and thymoma type (p < 0.05). We further analyzed the association between EBV infection and myasthenia gravis. However, it showed no significant difference(p = 0.2754), although the EBV infection rate was higher in the thymomas with myasthenia gravis.

Prognostic Correlation between Tumor Volume and Complete Resection of Thymoma at Different Masaoka-Koga Stages.

OBJECTIVE: Thymoma is a slow-growing epithelial tumor of thymus gland. Its size is associated with its prognosis. The aim of this study was to analyze the prognostic correlation of tumor volume and complete resection of thymoma at different Masaoka-Koga stages. METHODS: A retrospective study was carried out, using the data of 502 patients who underwent complete resection of thymectomy at Zhongshan Hospital, Fudan University, in Shanghai, China, from February 2009 to February 2016. The characteristics of the patients were collected. Using Masaoka-Koga staging system, patients were divided into four different subcohorts: Stage I, stage II, stage III and stage IVa/IVb. The relationship between tumor volume and postoperative recurrence was analyzed for each subcohort, using receiver operating curves, cutoff values were obtained. and patients were grouped according to the cutoff values. Survival analysis was performed with the help of Kaplan-Meier method, and the difference between the two survival curves was compared using log-rank test. Whether tumor volume could be used as an independent risk factor for thymoma prognosis was analyzed, using a univariate Cox proportional hazards model. RESULTS: The area under the curve was 0.718, 0.740, 0.798, and 0.804 for the stage I, II, III, and IVa/IVb subcohorts, respectively, and the cutoff values of tumor volume for predicting recurrence were 47.90 cm3, 53.70 cm3, 76.35 cm3, and 89.05 cm3, respectively. Patients with tumor volumes greater than the cutoff values had significantly shorter recurrence-free survival than those with tumor volumes less than the cutoff values (p < 0.001). The results of the univariate Cox proportional hazards model indicated that tumor volume was an independent risk factor for thymoma prognosis and for postoperative prognosis of thymoma in Masaoka-Koga stage I (p < 0.001). CONCLUSIONS: Tumor volume is significantly correlated with the postoperative prognosis of thymoma in Masaoka-Koga stage I and can serve as an independent risk factor for predicting postoperative tumor recurrence.

"One-Pot" In Situ Tandem Reaction─Dy(III) Coordination-Catalyzed Multicomponent Condensation of Salicylaldehyde Derivatives to Obtain Ketals.

It is difficult to subject simple reaction starting materials to a "one-pot" in situ tandem reaction without post-treatment under mild reaction conditions to obtain multimers with complex structural linkages. In organic synthesis, acetal reactions are often used to protect derivatives containing carbonyl functional groups. Therefore, acetal products tend to have very low stability, and performing multi-step condensation to obtain complex multimeric products is difficult. Herein, we achieved the first efficient multiple condensation of o-vanillin derivatives using Dy(OAc)3·6H2O undergoing a "one-pot" in situ tandem reaction under mild solvothermal conditions to obtain a series of dimers (I and II, clusters 1 and 2) and trimers (I and II, clusters 3 and 4). When methanol or ethanol is used as the solvent, the alcoholic solvent participates in acetal and dehydration reactions to obtain dimers (I and II). Surprisingly, when using acetonitrile as the reaction solvent, the o-vanillin derivatives undergo acetal and dehydration reactions to obtain trimers (I and II). In addition, clusters 1-4 all showed distinct single-molecule magnetic behaviors under zero-field conditions. To the best of our knowledge, this is the first time that multiple acetal reactions catalyzed by coordination-directed catalysis under "one-pot" conditions have been realized, opening a new horizon for the development of fast, facile, green, and efficient synthetic methods for complex compounds.

Novel Strategy To Inhibit Transthyretin Amyloidosis via the Synergetic Effect of Chemoselective Acylation and Noncovalent Inhibitor Release.

Strategies for developing targeted covalent inhibitors (TCIs), which have the advantages of a prolonged duration of action and selectivity toward a drug target, have attracted great interest in drug discovery. Herein, we report chemoselective covalent inhibitors that specifically target lysine ε-amine groups that conjugate with an endogenous protein to prevent disease-causing protein misfolding and aggregation. These TCIs are unique because the benzoyl group is preferentially conjugated to Lys15 at the top of the T4 binding site within transthyretin (TTR) while simultaneously releasing a potent noncovalent TTR kinetic stabilizer. The potency of these covalent inhibitors is superior to tafamidis, the only FDA-approved drug for the treatment of hereditary TTR amyloidosis. In addition to investigations into the covalent modification of TTR via reverse-phase high-performance liquid chromatography, direct methods are performed to confirm and visualize the presumed covalent interaction via mass spectrometry and X-ray crystallography.

Risk factors associated with low-level viremia in human immunodeficiency virus/acquired immunodeficiency syndrome patients after anti-retroviral therapy / 中华传染病杂志

Objective:To investigate the risk factors of low-level viremia (LLV) among human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients after combined anti-retroviral therapy (ART), and to provide evidence for reducing the risk of LLV.Methods:It was a cross-sectional observation study that enrolled HIV/AIDS patients with LLV (plasma HIV-1 RNA was 50 to 1 000 copies/mL) receiving ART over one year (LLV group) from January 2019 to December 2020 in Guangzhou Eighth People′s Hospital, Guangzhou Medical University. Contemporaneous patients with ART over one year and successful viral suppression (plasma HIV-1 RNA<50 copies/mL) were randomly selected as the control group (suppression group) with a ratio of 1∶2.5, and the risk factors for LLV were analyzed by unconditional logistic regression.Results:A total of 128 and 297 patients were enrolled in LLV group and the suppression group, respectively.ART durations were 3.62(1.83, 4.89) years and 4.91(2.90, 5.88) years, respectively. Multivariate logistic regression analysis showed that the risk factors associated with LLV included the age of initial ART treatment above 50 years old (odds ratio ( OR)=1.82, 95% confidence interval ( CI) 1.01 to 3.26, P=0.046), the baseline HIV-1 RNA over 1×10 5 copies/mL ( OR=2.18, 95% CI 1.30 to 3.68, P=0.003), using the simplified initial ART regimen ( OR=1.82, 95% CI 1.02 to 3.26, P=0.044), missing medication more than three times per year ( OR=2.49, 95% CI 1.55 to 4.01, P<0.001) and changing regimen during ART ( OR=1.90, 95% CI 1.14 to 3.14, P=0.013), while the duration of ART longer than five years could reduce the risk of LLV ( OR=0.37, 95% CI 0.22 to 0.64, P<0.001). In patients with simplified initial ART regimen, the baseline CD4 + T lymphocyte count of whom with LLV was lower than that of whom with viral suppression, and the difference was statistically significant (94.00 (24.00, 281.00)/μL vs 375.00 (310.00, 435.00)/μL, Z=-2.60, P<0.001). Conclusions:The occurrence of LLV is related to the age of initial ART treatment, the baseline HIV-1 RNA, the initial ART regimen, the medication adherence and the change of ART regimen during ART. Strategies may be beneficial to reducing the risk of LLV for HIV/AIDS patients, such as initiating ART as soon as possible, using simplified regimen as initial regimen with caution in patients with low baseline CD4 + T lymphocyte counts, strengthening compliance education, avoiding unnecessary ART regimen changes.

Incidence and factors associated with hepatitis B surface antigen seroclearance in patients co-infected with HBV/HIV during antiretroviral therapy in Guangdong, China / 中华医学杂志(英文版)

BACKGROUND@#Hepatitis B surface antigen (HBsAg) clearance is vital for a functional cure of hepatitis B virus (HBV) infection. However, the incidence and predictors of HBsAg seroclearance in patients co-infected with HBV and human immunodeficiency virus (HIV) remain largely unknown in Guangdong, China.@*METHODS@#Between 2009 and 2019, patients co-infected with HBV/HIV undergoing antiretroviral therapy (ART) in Guangzhou Eighth People's Hospital affiliated to Guangzhou Medical University were retrospectively reviewed with the endpoint on December 31, 2020. The incidence and risk factors for HBsAg seroclearance were evaluated using Kaplan-Meier and multivariate Cox regression analyses.@*RESULTS@#A total of 1550 HBV/HIV co-infected patients were included in the study, with the median age of 42 years and 86.0% (1333/1550) males. Further, 98.3% (1524/1550) received ART containing tenofovir disoproxil fumarate (TDF) plus lamivudine (3TC). HBV DNA was examined in 1283 cases at the last follow-up. Over the median 4.7 years of follow-up, 8.1% (126/1550) patients achieved HBsAg seroclearance, among whom 50.8% (64/126) obtained hepatitis B surface antibody, 28.1% (137/488) acquired hepatitis B e antigen seroconversion, and 95.9% (1231/1283) undetectable HBV DNA. Compared with patients who maintained HBsAg positive, cases achieving HBsAg seroclearance showed no differences in age, gender, CD4 + T cell count, alanine aminotransferase (ALT) level, or fibrosis status; however, they presented lower HBV DNA levels, lower HBsAg levels, and higher rates of HBV genotype B at the baseline. Multivariate analysis showed that baseline HBsAg <1500 cutoff index (COI) (adjusted hazard ratio [aHR], 2.74, 95% confidence interval [95% CI]: 1.48-5.09), ALT elevation >2 × upper limit of normal during the first six months after receiving ART (aHR, 2.96, 95% CI: 1.53-5.77), and HBV genotype B (aHR, 3.73, 95% CI: 1.46-9.59) were independent predictors for HBsAg seroclearance (all P <0.01).@*CONCLUSIONS@#Long-term TDF-containing ART has high anti-HBV efficacy including relatively high overall HBsAg seroclearance in HBV/HIV co-infected patients. Lower baseline HBsAg levels, HBV genotype B, and elevated ALT levels during the first six months of ART are potential predictors of HBsAg seroclearance.

Manipulating Solvothermal Coordination-Catalyzed In Situ Tandem Reactions to Construct Dysprosium-Based Complexes with Different Shapes and Zero-Field SMM Behaviors.

By changing the coordination anions (OAc- and Cl-), reaction temperature, solvent, and ligand substituents, four Dy(III)-based complexes were obtained by directed synthesis, which are [Dy4(L1)2(L2)2(OAc)4]·4C2H5OH·3H2O (1, L1 = 1,3,4-thiadiazole-2,5-diamine, H4L2 = 6,6'-(((1,3,4-thiadiazole-2,5-diyl)bis(azanediyl))bis(((3-ethoxy-2-hydroxybenzyl)oxy)methylene))bis(2-ethoxyphen), [Dy4(L3)4(OAc)4]·C2H5OH·H2O (2, H3L3 = 2-(((5-amino-1,3,4-thiadiazol-2-yl)amino)((3-ethoxy-2-hydroxybenzyl)oxy)methyl)-6-ethoxyphenol)), [Dy6(L4)4(L5)2(µ3-OH)4(CH3O)4Cl4]Cl2 (3, H2L4 = 2-hydroxy-3-methoxybenzaldehyde, H2L5 = 2-(((5-amino-1,3,4-thiadiazol-2-yl)amino)(hydroxy)methyl)-6-methoxyphenol), and [Dy6(L6)4(L7)2(µ3-OH)4(CH3O)4Cl4]Cl2·2H3O (4, H2L6 = 2-hydroxy-3-ethoxybenzaldehyde, H2L7 = 2-(((5-amino-1,3,4-thiadiazol-2-yl)amino)(hydroxy)methyl)-6-ethoxyphenol). A series of acetal products (H4L2, H3L3, H2L5, and H2L7) were obtained through dehydration in situ tandem reactions. Magnetic studies show that complexes 1-4 exhibited different single-molecule magnet behavior under zero-field conditions. The best fitting results showed that under zero DC field, the effective energy barriers (Ueff) and magnetic relaxation times (τ0) of complexes 1-4 are Ueff = 117.0 (2.1) K and τ0 = 6.07 × 10-7 s; Ueff = 83.91 (1.5) K and τ0 = 4.28 × 10-7 s; Ueff = 1.28 (0.2) K and τ0 = 0.73 s, and Ueff = 104.43 (13.3) K and τ0 = 8.25 × 10-8 s, respectively.

Hybrid purity identification using EST-SSR markers and heterosis analysis of quantitative traits of Russian wildrye.

Russian wildrye, Psathyrostachys junceus (Fisch.) Nevski, is widely distributed in the high latitude areas of Eurasia. It plays an important role in grassland ecosystem maintenance, as well as being a valuable palatable forage species for livestock and wildlife. Russian wildrye germplasm has rich phenotypic and genetic diversity and has potential for improvement through crossbreeding. In this study, fifteen Russian wildrye hybrid combinations were produced and one F1 population with 123 putative hybrids was obtained by crossing two individual plants with significant differences in nutritional characteristics and reproductive tiller number. Twelve phenotypic traits of the F1 population were measured for three consecutive years, and ten of the twelve traits were in line with the genetic characteristics of quantitative traits. Hybrid superiority was revealed among F1 hybrids in both nutritional and reproductive traits. One non-recurrent parent plant with the highest PCA-synthesis score was selected and used to make a backcross with the 'BOZOISKY SELECT' male parent, and 143 putative BC1 hybrids were obtained. Sixteen pairs of EST-SSR primers were randomly selected from polymorphic primers derived from different expressed tiller trait related genes. Three primer pairs that amplified both the paternal and maternal characteristic band were used to assess the purity of the F1 population, and three primer pairs (with one shared primer pair) were used to identify the BC1 population. The hybrid purity was 96.75% for the F1 population and 95.80% for the BC1 population, and the results were confirmed by self-fertility test through bagging isolation. The genetic similarity coefficients between the F1 progeny and the male parent ranged from 0.500 to 0.895, and those between the BC1 progeny and the male parent ranged from 0.667 to 0.939. A subset of individuals in the BC1 population had closer genetic distance to the recurrent parent, and genetic variation within the BC1 population decreased compared to the F1 population.

Anion-Manipulated Hydrolysis Process Assembles of Giant High-Nucleation Lanthanide-Oxo Cluster.

Widespread concern has been raised over the synthesis of highly nucleated lanthanide clusters with special shapes and/or specific linkages. Construction of lanthanide clusters with specific shapes and/or linkages can be achieved by carefully regulating the hydrolysis of lanthanide metal ions and the resulting hydrolysis products. However, studies on the manipulation of lanthanide-ion hydrolysis to obtain giant lanthanide-oxo clusters have been few. In this study, we obtained a tetraicosa lanthanide cluster (3) by manipulating the hydrolysis of Dy(III) ions using an anion (OAc-). As far as we know, cluster 3 has the highest nucleation among all lanthanide-oxo clusters reported. In 3, two triangular Dy3O4 are oriented in opposite directions to form the central connecting axis Dy6(OH)8, which is in turn connected to six Dy3O4 that are oriented in different directions. Meanwhile, a sample of a chiral trinuclear dysprosium cluster (1) was obtained in a mixed CH3OH and CH3CN solvent and by replacing the anion in the reaction to Cl- ions. In this cluster, 1,3,4-thiadiazole-2,5-diamine (L2) is free on one side through π···π interactions and is parallel to the o-vanillin (L1)- ligand, thus resulting in a triangular arrangement. The arrangement of L2 affects the end group coordination in the cluster 1 structure through hydrogen bonding and induces the cluster to exhibit chirality. When the reaction solvent was changed to CH3OH, a sample of cluster 2, composed of two independent triangular Dy3 that have different end group arrangements, was obtained. Magnetic analysis showed that clusters 1 and 3 both exhibit distinctive single-molecule magnetic properties under zero-magnetic-field conditions. This study thus provides a method for the creation of chiral high-nucleation clusters from achiral ligands and potentially paves the way for the synthesis of high-nucleation lanthanide clusters with unique forms.

Evolving SARS-CoV-2 virulence among hospital and university affiliates in Spain and Greater Boston

BackgroundThe COVID-19 pandemic caused by the SARS-CoV-2 virus greatly affected healthcare workers and healthcare systems. It also challenged schools and universities worldwide negatively affecting in-person education. We conducted this study is to assess the evolution of SARs-CoV-2 virulence over the course of the pandemic. MethodsA combined cohort of affiliates from the University of Navarra, two hospitals in Spain, and one healthcare system in the Greater Boston area was followed prospectively from March 8th, 2020, to January 31st, 2022 for diagnosis with COVID-19 by PCR testing and related sequelae. Follow-up time was divided into four periods according to distinct waves of infection during the pandemic. Severity of COVID-19 was measured by case-hospitalization rate. Descriptive statistics and multivariable-adjusted statistics using the Poisson mixed-effects regression model were applied. ResultsFor the last two periods of the study (January 1st to December 15th, 2021 and December 16th, 2021 to January 31st, 2022) and relative to the first period (March 8th to May 31st, 2020), the incidence rate ratios (IRRs) of hospitalization were 0.08 (95% CI, 0.03-0.17) and 0.03 (95% CI, 0.01-0.15), respectively. InterpretationThe virulence of COVID-19 and immunity of our populations evolved over time, resulting in a decrease in case severity. We found the case-hospitalization rate decreased more than 90% in our cohort despite an increase in incidence.

Alkali metal-linked triangular building blocks assemble a high-nucleation lanthanoid cluster based on single-molecule magnets.

The metallic central magnetic axes in high-nucleation clusters with complex structural connections tend to be disorganized and cancel each other out. Therefore, high-nucleation clusters cannot easily exhibit single-molecule magnets (SMMs) behaviors. Herein, we select a triple-core building block (Dy3K2, 1) and use linked diamagnetic alkali metal to form an open, spherical, high-nucleation cluster Dy12Na6 (3) with SMM behavior. Furthermore, by changing the reaction conditions, Dy6K2 (2) formed by linking two Dy3 by K(I) is obtained. High-resolution electrospray mass spectrometry of clusters 1-3 effectively captures the building block Dy3, and clusters 1 and 3 and Dy3 have high stability even with the increase in ion source energy. To the best of our knowledge, this is the first time that an SMM based on a high-nucleation cluster has been obtained by connecting magnetic primitives via diamagnetic metal ions. Dy12K6 is currently the highest nuclear ns-4f heterometallic SMM.

Assembly of pinwheel/twist-shaped chiral lanthanide clusters with rotor structures by an annular/linear growth mechanism and their magnetic properties.

Although progress has been made in the design and synthesis of chiral lanthanide clusters with pleasing structural connections and special shapes, assembly rules that guide their directional construction are still lacking. We reacted R/S-mandelic acid hydrazide, 2,3-dihydroxybenzaldehyde and DyCl3·6H2O under solvothermal conditions to obtain two octanuclear chirality clusters R-1 and S-1, which are the enantiomers of each other. R/S-mandelic acid hydrazide and 2,3-dihydroxybenzaldehyde underwent an in situ reaction under "one-pot" conditions to generate a monohydrazone-type organic ligand R/S-mandelic acid hydrazide-2,3-dihydroxybenzaldehyde hydrazone (R/S-H2L). Four R/S-H2L ligands captured eight metal-centered Dy(III) ions and presented an annular arrangement, which assembled to form a pinwheel-shaped chiral cluster R/S-1. The benzene rings at the four vertices of R/S-1 can rotate freely as rotors. This is the first discovery of an annular growth mechanism during the self-assembly of lanthanide clusters. By changing the metal salt to Dy(NO3)3·6H2O, two twist-shaped hexanuclear clusters R-2 and S-2, which are the enantiomers of each other were obtained. Four R/S-H2L and two R/S-H3L ligands captured six metal-centered Dy(III) ions, respectively, and were assembled through a linear growth mechanism to form the twist-shaped chiral clusters R/S-2. This is the first time that a linear growth mechanism has been proposed for the directional construction of lanthanide clusters with specific shapes. Circular dichroism results showed that R/S-1 and R/S-2 were both chiral clusters and enantiomers of each other. Magnetic studies showed that both R/S-1 and R/S-2 exhibit obvious single-molecule magnet (SMM) behaviors under zero-field conditions. This work is the first to propose an annular/linear growth mechanism for the design and synthesis of lanthanide clusters and allows the directional construction of chiral lanthanide clusters with special shapes and structural connections.

Analysis of controlling genes for tiller growth of Psathyrostachys juncea based on transcriptome sequencing technology.

BACKGROUND: Tillering is a complicated process in plant and is a significant trait that affects biomass and seed yield of bunch grass Psathyrostachys juncea, a typical perennial forage species. To clarify the regulatory mechanisms of tillering in P. juncea and to explore related candidate genes could be helpful to improve the seed and forage yield of perennial gramineous forages. We selected the tiller node tissues of P. juncea for transcriptome sequencing to determine the differentially expressed genes (DEG) between dense and sparse tillering genotypes. The metabolic pathway was studied, candidate genes were screened, and reference genes stability were evaluated. RESULTS: The results showed that approximately 5466 DEGs were identified between the two genotypes with dense and sparse tillers of P. juncea, which significantly differed in tiller number. Tillering regulation pathways analysis suggested that DEGs closely related to the biosynthesis of three plant hormones, namely auxin (IAA), cytokinin (CTK), and strigolactones (SLs), while "biosynthesis of lignin" and "nitrogen metabolism" have remarkable differences between the dense and sparse tillering genotypes. Meanwhile, the reference gene Actin1, having the best stability, was screened from twelve genes with highest expression level and was used in verification of ten tillering related candidate genes. CONCLUSIONS: The tillering mechanism of perennial grass P. juncea was expounded by transcriptome analysis of tiller node tissues. We demonstrated that dense-tillering genotypes may be distinguished by their low expression patterns of genes involved in SL, IAA, and high expression patterns of genes involved in CTK biosynthesis at the tillering stage, and nitrogen metabolism and lignin biosynthesis can also affect the number of tillers. Furthermore, the expression level of ten tillering related candidate genes were verified using Actin1 as reference gene. These candidate genes provide valuable breeding resources for marker assisted selection and yield traits improvement of P. juncea.