Giant thermal Hall conductivity in the pseudogap phase of cuprate superconductors.

The nature of the pseudogap phase of the copper oxides ('cuprates') remains a puzzle. Although there are indications that this phase breaks various symmetries, there is no consensus on its fundamental nature1. Fermi-surface, transport and thermodynamic signatures of the pseudogap phase are reminiscent of a transition into a phase with antiferromagnetic order, but evidence for an associated long-range magnetic order is still lacking2. Here we report measurements of the thermal Hall conductivity (in the x-y plane, κxy) in the normal state of four different cuprates-La1.6-xNd0.4SrxCuO4, La1.8-xEu0.2SrxCuO4, La2-xSrxCuO4 and Bi2Sr2-xLaxCuO6+δ. We show that a large negative κxy signal is a property of the pseudogap phase, appearing at its critical hole doping, p*. It is also a property of the Mott insulator at p ≈ 0, where κxy has the largest reported magnitude of any insulator so far3. Because this negative κxy signal grows as the system becomes increasingly insulating electrically, it cannot be attributed to conventional mobile charge carriers. Nor is it due to magnons, because it exists in the absence of magnetic order. Our observation is reminiscent of the thermal Hall conductivity of insulators with spin-liquid states4-6, pointing to neutral excitations with spin chirality7 in the pseudogap phase of cuprates.

Thermodynamic signatures of quantum criticality in cuprate superconductors.

The three central phenomena of cuprate (copper oxide) superconductors are linked by a common doping level p*-at which the enigmatic pseudogap phase ends and the resistivity exhibits an anomalous linear dependence on temperature, and around which the superconducting phase forms a dome-shaped area in the phase diagram1. However, the fundamental nature of p* remains unclear, in particular regarding whether it marks a true quantum phase transition. Here we measure the specific heat C of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range2 that includes p*. As a function of doping, we find that Cel/T is strongly peaked at p* (where Cel is the electronic contribution to C) and exhibits a log(1/T) dependence as temperature T tends to zero. These are the classic thermodynamic signatures of a quantum critical point3-5, as observed in heavy-fermion6 and iron-based7 superconductors at the point where their antiferromagnetic phase comes to an end. We conclude that the pseudogap phase of cuprates ends at a quantum critical point, the associated fluctuations of which are probably involved in d-wave pairing and the anomalous scattering of charge carriers.

Exotic Magnetism in Perovskite KOsO_{3}.

A new perovskite KOsO_{3} has been stabilized under high-pressure and high-temperature conditions. It is cubic at 500 K (Pm-3m) and undergoes subsequent phase transitions to tetragonal at 320 K (P4/mmm) and rhombohedral (R-3m) at 230 K as shown from refining synchrotron x-ray powder diffraction (SXRD) data. The larger orbital overlap integral and the extended wave function of 5d electrons in the perovskite KOsO_{3} allow to explore physics from the regime where Mott and Hund's rule couplings dominate to the state where the multiple interactions are on equal footing. We demonstrate an exotic magnetic ordering phase found by neutron powder diffraction along with physical properties via a suite of measurements including magnetic and transport properties, differential scanning calorimetry, and specific heat, which provide comprehensive information for a system at the crossover from localized to itinerant electronic behavior.

Evidence for Band Renormalizations in Strong-Coupling Superconducting Alkali-Fulleride Films.

There has been a long-standing debate about the mechanism of the unusual superconductivity in alkali-intercalated fullerides. In this Letter, using high-resolution angle-resolved photoemission spectroscopy, we systematically investigate the electronic structures of superconducting K_{3}C_{60} thin films. We observe a dispersive energy band crossing the Fermi level with the occupied bandwidth of about 130 meV. The measured band structure shows prominent quasiparticle kinks and a replica band involving the Jahn-Teller active phonon modes, which reflects strong electron-phonon coupling in the system. The electron-phonon coupling constant is estimated to be about 1.2, which dominates the quasiparticle mass renormalization. Moreover, we observe an isotropic nodeless superconducting gap beyond the mean-field estimation (2Δ/k_{B}T_{c}≈5). Both the large electron-phonon coupling constant and large reduced superconducting gap suggest a strong-coupling superconductivity in K_{3}C_{60}, while the electronic correlation effect is suggested by the observation of a waterfall-like band dispersion and the small bandwidth compared with the effective Coulomb interaction. Our results not only directly visualize the crucial band structure but also provide important insights into the mechanism of the unusual superconductivity of fulleride compounds.

Observation of Vector Spin Seebeck Effect in a Noncollinear Antiferromagnet.

Spintronic phenomena to date have been established in magnets with collinear moments, where the spin injection through the spin Seebeck effect (SSE) is always along the out-of-plane direction. Here, we report the observation of a vector SSE in a noncollinear antiferromagnet (AF) LuFeO_{3}, where temperature gradient along the out-of-plane and also the in-plane directions can both inject a pure spin current and generate a voltage in the heavy metal via the inverse spin Hall effect (ISHE). We show that the thermovoltages are due to the magnetization from canted spins in LuFeO_{3}. Furthermore, in contrast to the challenges of generating, manipulating, and detecting spin current in collinear AFs, the vector SSE in LuFeO_{3} is readily viable in zero magnetic field and can be controlled by a small magnetic field of about 150 Oe at room temperature. The noncollinear AFs expand new realms for exploring spin phenomena and provide a new route to low-field antiferromagnetic spin caloritronics and magnonics.

[Significance of aspergillus fumigatus-specific IgG in the diagnosis of allergic bronchopulmonary aspergillosis].

The data of 18 patients with allergic bronchopulmonary aspergillosis (ABPA) who received aspergillus fumigatus-specific IgG detection from 2015 to 2021 in Peking University Third Hospital were retrospectively analyzed. Among them, 11 were male and 7 were female, aged 18-79 years. All patients had a history of asthma or symptoms of cough and asthma, and aspergillus fumigatus-specific IgE was positive; 16 patients had total serum IgE>500 U/ml, of which 13 patients had total serum IgE>1 000 U/ml. Among other diagnostic indicators, peripheral blood eosinophils were >0.5×109/L in 16 cases; lung CT showed bronchiectasis in 15 cases; serum aspergillus fumigatus-specific IgG was positive (>120 AU/ml) in 10 cases. There was no significant difference in serum total IgE level, peripheral blood eosinophil count, and bronchiectasis ratio between positive and negative cases of aspergillus fumigatus-specific IgG (all P>0.05). In this study, the positive rate of aspergillus fumigatus-specific IgG in patients with ABPA was more than 50%, which has auxiliary value in the diagnosis of ABPA.

[Analysis of syphilis antibody screening results of outpatients and inpatients in a hospital in Beijing from 2016 to 2020].

Objective: The results of syphilis antibody screening in Peking University Third Hospital from 2016 to 2020 were analyzed,to explore the characteristics of sex, age and distribution of patients with positive syphilis antibody. Methods: A retrospective study was conducted to collect the results of syphilis antibody in outpatients and inpatients of Peking University Third Hospital from 2016 to 2020. Syphilis antibodies were screened in 626 528 patients aged 1-98 years, 4 232 were retested positive by TPPA test, including 2 132 males (50.4%) and 2 100 females (49.6%). Chemiluminescence immunoassay (CMIA) was used for syphilis antibody screening, and Treponema pallidum particle agglutination (TPPA) test was used for reexamination. SPSS20.0 data statistical analysis software was used to analyze the detection rate, age, sex, department and clinical diagnosis of patients with positive syphilis antibody by χ² test. Results: Among 626 528 patients who were positive for treponema pallidum antibody screening, 4 232 were retested positive by TPPA test, accounting for 0.68% of the total number of patients tested. The number of syphilis tests increased year by year, however the positive detection rate decreased. The positive detection rate of syphilis antibody in 2020 decreased by 18.9% compared with 2016. The positive rate of syphilis antibody in male patients was higher than that in female patients, accounting for 0.80% and 0.59% of the total number of patients tested respectively. The positive rate of syphilis antibody of different genders increased with age, the total positive rate of 0-20, 21-40, 41-60, 61-80,>80 years old were 0.15%, 0.45%, 0.95%, 1.07% and 1.41%, respectively. While the increase rate of males was higher than that of females. The positive rate of male over 80 years old was 18.13 times of the group of 0-20 years old, and 5.54 times in women. The top 6 departments with positive syphilis antibody detection rate were emergency department, oncology department, respiratory department, geriatrics department, endocrinology department and neurology department, and the positive rates were 1.79% (104/5 810),1.46% (55/3 767),1.20% (74/6 167),1.20% (22/1 833),1.10% (32/2 909),1.09% (94/8 624), respectively. From the analysis of clinical diagnosis, the proportion of positive syphilis antibody in infertile patients (0.64%, 672/104 911) was higher than that in naturally conceived patients (0.10%, 24/23 969). Conclusions: From 2016 to 2020, the positive detection rate of syphilis antibody in Peking University Third Hospital decreased year by year. However, the positive detection rate increased with the age of patients. The positive rate of syphilis antibody in male was higher than that in female. The positive rate of syphilis antibody in pregnant women was lower than that in infertile patients.

[Analysis of related risk factors in the occurrence of mercury-toxic nephrotic syndrome].

Objective: To analyse the clinical characteristics of mercury-toxic nephrotic syndrome and to find the risk factors. Methods: A total of 126 patients with mercury-toxic admitted to Beijing Chaoyang Hospital from January 2017 to January 2020 were selected as the research objectives. General data such as age, gender, mercury exposure history of all patients and laboratory data such as urine mercury and urine creatinine were collected. The clinical manifestations and pathological types of patients with mercury-toxic nephrotic syndrome were analyzed, and the risk factors of mercury-toxic nephrotic syndrome were found by univariate and multivariate logistic regression analysis. Results: Among the 24 patients with mercury-toxic nephrotic syndrome, 1 was poisoned by respiratory tract, 6 were poisoned by digestive tract, and 17 were poisoned by skin absorption. In addition to the manifestations of kidney injury, some of the patients also showed neurological symptoms such as dizziness, fatigue, hand tremor, and limb pain. The main pathological types were membranous nephropathy (9 cases) and micropathological nephropathy (10 cases) . The results of multivariate logistic regression analysis showed that the digestive tract and skin absorption pathways of mercury were risk factors for mercury-toxic nephrotic syndrome (OR=21.099, 23.840, P<0.05) . Conclusion: The absorption pathway of mercury has an important influence on the pathogenesis of mercury-toxic nephrotic syndrome, especially in patients with mercury poisoning absorbed by the skin and digestive tract, the risk of complicating nephrotic syndrome is higher.

MicroRNA-4443 regulates monocyte activation by targeting tumor necrosis factor receptor associated factor 4 in stroke-induced immunosuppression.

BACKGROUND AND PURPOSE: MicroRNAs (miRNAs) have been demonstrated to play crucial roles in the early stage of acute ischaemic stroke (AIS). The purpose of this study was to investigate the expression patterns of miRNAs in peripheral blood mononuclear cells (PBMCs) from AIS patients and further explore related molecular mechanisms in stroke-induced immunodeficiency syndrome (SIDS). METHODS: The miRNA expression patterns of PBMCs were detected by miRNA microarray and validated by quantitative real-time polymerase chain reaction (qRT-PCR) in AIS patients and healthy controls. Bioinformatics methods and luciferase reporter assays were used to detect the downstream target genes. Following stimulation with lipopolysaccharide and interleukin-4, the expression of miR-4443, tumor necrosis factor receptor associated factor 4 (TRAF4) and the nuclear factor kappa B (NF-κB) pathway were evaluated. Furthermore, transfection with miR-4443 mimic or inhibitor in the monocytes was carried out to gain insight into the mechanisms in SIDS. RESULTS: Interleukin-10 in AIS patients was significantly higher than that of healthy controls. The miRNA microarray analysis and qRTPCR validation showed that only miR-4443 was upregulated expressed in PBMCs from AIS patients, especially in monocytes. miR-4443 was shown to directly interact with the 3' untranslated regions of TRAF4, resulting in suppression of TRAF4 protein expression. Furthermore, the expression of miR-4443 and TRAF4 was regulated by stimulation with lipopolysaccharide or interleukin-4. Additionally, overexpression of miR-4443 suppressed the TRAF4/Iκα/NF-κB signaling pathway to activate the expression of anti-inflammatory cytokines in monocytes. CONCLUSIONS: The increased expression of miR-4443 induced monocyte dysfunction by targeting TRAF4, which may function as a crucial mediator in SIDS.

Biological Characteristics and Genetic Diversity of Phomopsis asparagi, Causal Agent of Asparagus Stem Blight.

Asparagus stem blight is a regional disease. In the present study, we compared strains of Phomopsis asparagi from six different provinces to determine their biological characteristics and genetic diversity, differences in the pycnidium and conidium production, pathogenicity, and growth rate. Considerable differences were established in the pycnidium and conidium production among the P. asparagi strains from the six studied provinces. The largest pycnidium and conidium production had the strains from Fujian, followed by those from Hainan. The virulence of P. asparagi strains was significantly different but without a correlation with the geographical source of the strain. FJ2 had the highest virulence, followed by HN2, SD4, and SD5, whereas SD5 had the lowest virulence. The colony diameter and dry weight of the strains of asparagus stem blight fungus from the six provinces were substantially different. The colonies of HN1-5 had the largest diameters, whereas those of XT1-5, LT1-3, FJ1-5, and SX6 had smaller diameters. Four primers with good repeatability and strong specificity were selected from 100 intersimple sequence repeat (ISSR) primers. ISSR-PCR amplification was performed on 36 strains of asparagus stem blight fungus, and a large number of repeatable DNA fingerprints were obtained. Most of the amplified fragments were within 300 to 500 bp. In all, 69 total points, 64 multiple points, and 92.75% polymorphism points were established. The number of ISSR gene sites detected by four primers ranged from 14 to 20, with an average of 16 multiple sites. The copolymerization was divided into three groups: XT1-5, LT1-3, and FJ1-5, which were clustered into the first group; SD1-6, SX1-6, and HB1-6, clustered into the second group; and HN1-5 in the third group. The results of the cluster analysis revealed that the strains of the neighboring provinces had a nearer phylogenetic relationship than that between distant ones. Therefore, the system evolution of P. asparagi is related to the geographical distribution of its strains.

Factors Influencing the Initiation Time of Forensic Psychiatric Assessment of Criminal Cases in Hunan Province.

ABSTRACT: Objective To discuss the related factors influencing the initiation time of forensic psychiatric assessment by analysis of the initiation time of forensic psychiatric assessment of criminal cases in Hunan Province. Methods Related data in assessment files of criminal cases accepted by 8 forensic psychiatric assessment institutions in Hunan Province from January 1, 2011 to December 31, 2016 were extracted. The Logistic regression analysis was used to explore the factors influencing the initiation time of forensic psychiatric assessment. After using property score matching （PSM） to control the influence of confounding factors, the efficiency of public security organs to initiate assessments of suspects with （without） mental disorders and with （without） responsibilities were compared. Results A total of 4 346 cases were included. The Logistic regression analysis suggested that the factors independently related to the initiation time of assessment include： cause of assessment, nationality of the assessed, history of diagnosis and treatment of mental illnesses, history of crimes, history of drug abuse, and status of alcohol consumption before the crime （all P<0.05）. The initiation time of assessment of suspects diagnosed with mental disorder was shorter than those with none （P<0.05）; the initiation time of assessment of suspects without criminal responsibility was shorter than those with responsibility （P<0.05）. After using PSM to control confounding factors, the differences above still existed. Conclusion The cause of assessment, nationality of the assessed, history of diagnosis and treatment of mental illnesses, history of crimes, history of drug abuse, and status of alcohol consumption before the crime are factors that influence the efficiency of public security organs to initiate forensic psychiatric assessments. Under the current assessment initiation mode, forensic psychiatric assessment of suspects who have mental disorders, especially those with no responsibility may be given priority to initiate.

Charge disproportionation and the pressure-induced insulator-metal transition in cubic perovskite PbCrO3.

The perovskite PbCrO3 is an antiferromagnetic insulator. However, the fundamental interactions leading to the insulating state in this single-valent perovskite are unclear. Moreover, the origin of the unprecedented volume drop observed at a modest pressure of P = 1.6 GPa remains an outstanding problem. We report a variety of in situ pressure measurements including electron transport properties, X-ray absorption spectrum, and crystal structure study by X-ray and neutron diffraction. These studies reveal key information leading to the elucidation of the physics behind the insulating state and the pressure-induced transition. We argue that a charge disproportionation 3Cr(4+) → 2Cr(3+) + Cr(6+) in association with the 6s-p hybridization on the Pb(2+) is responsible for the insulating ground state of PbCrO3 at ambient pressure and the charge disproportionation phase is suppressed under pressure to give rise to a metallic phase at high pressure. The model is well supported by density function theory plus the correlation energy U (DFT+U) calculations.

Regulatory role of B-cell maturation antigen on the toxic effect of chromium ions on human SaOS-2 osteoblasts.

Metal prostheses of artificial joints undergo wear, producing numerous metal particles and ions, such as Cr3+ . Cr3+ is considered a key factor leading to aseptic loosening. Many studies focus on the effect of Cr3+ on osteoblasts; however, little is known about the effect of Cr3+ on the B-cell maturation antigen (BCMA) in the osteoblasts. In this study, we first demonstrated the BCMA expressed in human SaOS-2 osteoblasts through reverse transcriptase-PCR, Western blot, and immunocytochemical analyses. Cr3+ decreased alkaline phosphatase (ALP), osteocalcin (OC), cell mineralization, and collagen type I mRNA and protein expression. Moreover, Cr3+ has an inhibitive effect on the expression of the BCMA in human SaOS-2 osteoblasts. However, after we upregulated the expression of the BCMA, ALP, OC, cell mineralization, and collagen type I mRNA and protein expression were increased. Overall, this study demonstrates that the BCMA is involved in human SaOS-2 osteoblast osteogenetic metabolism and plays a regulatory role on the toxic effect of chromium ions on human SaOS-2 osteoblasts.

Slater Insulator in Iridate Perovskites with Strong Spin-Orbit Coupling.

The perovskite SrIrO_{3} is an exotic narrow-band metal owing to a confluence of the strengths of the spin-orbit coupling (SOC) and the electron-electron correlations. It has been proposed that topological and magnetic insulating phases can be achieved by tuning the SOC, Hubbard interactions, and/or lattice symmetry. Here, we report that the substitution of nonmagnetic, isovalent Sn^{4+} for Ir^{4+} in the SrIr_{1-x}Sn_{x}O_{3} perovskites synthesized under high pressure leads to a metal-insulator transition to an antiferromagnetic (AF) phase at T_{N}≥225 K. The continuous change of the cell volume as detected by x-ray diffraction and the λ-shape transition of the specific heat on cooling through T_{N} demonstrate that the metal-insulator transition is of second order. Neutron powder diffraction results indicate that the Sn substitution enlarges an octahedral-site distortion that reduces the SOC relative to the spin-spin exchange interaction and results in the type-G AF spin ordering below T_{N}. Measurement of high-temperature magnetic susceptibility shows the evolution of magnetic coupling in the paramagnetic phase typical of weak itinerant-electron magnetism in the Sn-substituted samples. A reduced structural symmetry in the magnetically ordered phase leads to an electron gap opening at the Brillouin zone boundary below T_{N} in the same way as proposed by Slater.

Lattice effects on ferromagnetism in perovskite ruthenates.

Ferromagnetism and its evolution in the orthorhombic perovskite system Sr(1-x)Ca(x)RuO3 have been widely believed to correlate with structural distortion. The recent development of high-pressure synthesis of the Ba-substituted Sr(1-y)Ba(y)RuO3 makes it possible to study ferromagnetism over a broader phase diagram, which includes the orthorhombic Imma and the cubic phases. However, the chemical substitutions introduce the A-site disorder effect on Tc, which complicates determination of the relationship between ferromagnetism and structural distortion. By clarifying the site disorder effect on Tc in several unique series of ruthenates in which the average bond length remains the same but the bond-length variance varies, we are able to demonstrate a parabolic curve of Tc versus mean bond length . A much higher Tc ∼ 177 K than that found in orthorhombic SrRuO3 can be obtained from the curve at a bond length , which makes the geometric factor t = /(√2) ∼ 1. This result reveals not only that the ferromagnetism in the ruthenates is extremely sensitive to the lattice strain, but also that it has an important implication for exploring the structure-property relationship in a broad range of oxides with perovskite or a perovskite-related structure.

Anomalous perovskite PbRuO3 stabilized under high pressure.

Perovskite oxides ABO3 are important materials used as components in electronic devices. The highly compact crystal structure consists of a framework of corner-shared BO6 octahedra enclosing the A-site cations. Because of these structural features, forming a strong bond between A and B cations is highly unlikely and has not been reported in the literature. Here we report a pressure-induced first-order transition in PbRuO3 from a common orthorhombic phase (Pbnm) to an orthorhombic phase (Pbn21) at 32 GPa by using synchrotron X-ray diffraction. This transition has been further verified with resistivity measurements and Raman spectra under high pressure. In contrast to most well-studied perovskites under high pressure, the Pbn21 phase of PbRuO3 stabilized at high pressure is a polar perovskite. More interestingly, the Pbn21 phase has the most distorted octahedra and a shortest Pb-Ru bond length relative to the average Pb-Ru bond length that has ever been reported in a perovskite structure. We have also simulated the behavior of the PbRuO3 perovskite under high pressure by first principles calculations. The calculated critical pressure for the phase transition and evolution of lattice parameters under pressure match the experimental results quantitatively. Our calculations also reveal that the hybridization between a Ru:t2g orbital and an sp hybrid on Pb increases dramatically in the Pbnm phase under pressure. This pressure-induced change destabilizes the Pbnm phase to give a phase transition to the Pbn21 phase where electrons in the overlapping orbitals form bonding and antibonding states along the shortest Ru-Pb direction at P > Pc.

Enhancement of the Nernst effect by stripe order in a high-T(c) superconductor.

The Nernst effect in metals is highly sensitive to two kinds of phase transition: superconductivity and density-wave order. The large, positive Nernst signal observed in hole-doped high-T(c) superconductors above their transition temperature (T(c)) has so far been attributed to fluctuating superconductivity. Here we report that in some of these materials the large Nernst signal is in fact the result of stripe order, a form of spin/charge modulation that causes a reconstruction of the Fermi surface. In La(2-x)Sr(x)CuO(4) (LSCO) doped with Nd or Eu, the onset of stripe order causes the Nernst signal to change from being small and negative to being large and positive, as revealed either by lowering the hole concentration across the quantum critical point in Nd-doped LSCO (refs 6-8) or by lowering the temperature across the ordering temperature in Eu-doped LSCO (refs 9, 10). In the second case, two separate peaks are resolved, respectively associated with the onset of stripe order at high temperature and superconductivity near T(c).

Effects of thrombin on the secondary cerebral injury of perihematomal tissues of rats after intracerebral hemorrhage.

This study aimed to investigate the effects of thrombin released in hematoma after intracerebral hemorrhage (ICH) on the cerebral injury of perihematomal tissues and to evaluate the protection effect of hirudin on the cerebral injury after ICH. We used the autologous uncoagulated blood injection method to prepare the ICH rat model, and all rats were randomly divided into a normal group, an ICH group, or a hirudin group. At different time points, rat heads were cut to harvest brain sections. Immunohistochemical staining, histochemical staining, and hematoxylin and eosin staining were conducted for CD34, microglia, and neutrocytes. CD34-positive microvessels were most abundant in brain tissues of the sham-operation group. At 12 h after ICH, CD34 expression reduced and reached the minimum level at 72 h (P<0.01). At 6 h after ICH, microglia expression was visible and reached a peak at 48 h (P<0.01). At 12 h after ICH, neutrocyte infiltration was visible and the number was greatest at 48 h (P<0.01). The early application of hirudin after ICH could significantly reduce microglia and neutrocyte expression and could significantly slow down the CD34 decrease trend (P<0.01). However, hirudin application in the edematization stage after ICH did not significantly increase CD34- positive microvessel abundance (P>0.05). A thrombin-mediated inflammatory reaction is involved in the cerebral injury after ICH, and the early application of hirudin has a protective effect.

MTHFR C677T polymorphism and osteoporotic fracture in postmenopausal women: a meta-analysis.

Numerous studies have evaluated the association between MTHFR C677T polymorphism and osteoporotic fracture risk in postmenopausal women. However, the results have been inconsistent. We performed a meta-analysis of the association between MTHFR C677T polymorphism and osteoporotic fracture risk in postmenopausal women. Only seven case-control studies were retrieved, with a total of 4258 patients and 3454 healthy controls. Meta-analysis results showed no significant association between MTHFR C677T polymorphism and osteoporotic fracture risk in postmenopausal women for all genetic models (for TT vs CC: OR=0.99, 95%CI=0.72-1.39; for TT vs TC: OR=1.02, 95%CI=0.87-1.20; for CC+TC vs TT: OR=0.96, 95%CI=0.71-1.28; for TT+TC vs CC: OR=0.93, 95%CI=0.84-1.03). In the subgroup analysis by ethnicity, the results also showed no significant association between MTHFR C677T polymorphism and susceptibility to osteoporotic fracture in postmenopausal women in both Caucasian and Asian populations. In conclusion, this meta-analysis suggests that MTHFR C677T polymorphism may not be associated with susceptibility to osteoporotic fracture in postmenopausal women.

Identification and analysis of a 5-bp indel of a porcine BMP7 gene promoter.

Bone morphological protein7 (BMP7), a member of the transforming growth factor-ß (TGF-ß) family, was first identified because of its ability to induce ectopic chondro-osteogenesis in vivo. It also plays a crucial role in the growth, development, and physiological functioning of the reproductive system. Among intra-ovarian growth factors, many studies have shown that BMP7 plays a pivotal role in regulating the early phases of follicular growth. We detected a 5-bp insertion-deletion at 602 bp upstream from the transcription start site of the BMP7 gene promoter among 258 pigs of 3 breeds. Along with 2 homoduplex DNAs, another 4 previously unknown bands (named A, B, C, and D) were detected by non-denaturing polyacrylamide gel electrophoresis. By DNA sequencing, we found that PCR products from heterozygotes contained 2 homoduplexes and 4 heteroduplexes. Genetic polymorphism analysis revealed 3 genotypes (AA, AB, and BB) at this site; the distribution of these genotypes followed Hardy-Weinberg equilibrium. A was the dominant allele (0.715), and AA was the dominant genotype (0.500). The polymorphism information content value was calculated to be 0.325, the expected heterozygosity was 0.407, and effective number of alleles was 1.688, indicating an intermediate degree of polymorphism and good potential for selection and breeding. Highly significant differences were found between different breeds and distributions of genotypes. Based on correlation analysis, the 5-bp indel site does not significantly affect porcine reproductive traits (total number of births, number of piglets born alive, litter birth weight, and litter weight at 21 days; P>0.05), which was consistent with the results of genetic variation analysis.