Divergent Synthesis of Scabrolide A and Havellockate via an exo-exo-endo Radical Cascade.

Here we report a concise and divergent synthesis of scabrolide A and havellockate, representative members of polycyclic marine natural product furano(nor)cembranoids. The synthesis features a highly efficient exo-exo-endo radical cascade. Through the generation of two rings, three C-C bonds, and three contiguous stereocenters in one step, this remarkable transformation not only assembles the bowl-shaped, common 6-5-5 fused ring system from simple building blocks but also precisely installs the functionalities at desired positions and sets the stage for further divergent preparation of both target molecules. Further studies reveal that the robust and unusual 6-endo radical addition in the cascade is likely facilitated by the rigidity of the substrate.

Risk factors for surgical site infection after percutaneous endoscopic lumbar discectomy.

The objective of this study was to investigate the risk factors associated with surgical site infection (SSI) after percutaneous endoscopic lumbar discectomy (PELD) in patients with lumbar disc herniation (LDH). A retrospective analysis was performed on a cohort of 335 patients who underwent PELD between January 2016 and January 2023. Data were derived from the Hospital Information System (HIS), and a comprehensive statistical assessment was performed using IBM SPSS Statistics version 25.0. Both univariate and multivariate logistic regression analyses assessed a range of risk determinants, such as age, body mass index (BMI), comorbidities, laboratory test parameters and surgery-related variables. The incidence of SSI after PELD was 2.7% (9/335). Univariate analysis highlighted BMI, diabetes mellitus, long-term corticosteroid consumption, surgical time and cerebrospinal fluid leakage as significant predictors of SSI. Multivariate logistic regression identified BMI, diabetes mellitus, long-term corticosteroid consumption, surgical time and cerebrospinal fluid leakage as significant risk factors for SSI after PELD. High BMI, diabetes mellitus, long-term corticosteroid consumption, long surgical time and postoperative cerebrospinal fluid leakage are predisposing factors for SSI in patients undergoing PELD. Precise interventions focused on such risk components, including careful preoperative assessment and strategic postoperative care, are essential to reduce the incidence of SSI and improve surgical efficacy.

Efficient Non-dissociative Activation of Dinitrogen to Ammonia over Lithium-Promoted Ruthenium Nanoparticles at Low Pressure.

There is an exciting possibility to decentralize ammonia synthesis for fertilizer production or energy storage without carbon emission from H2 obtained from renewables at small units operated at lower pressure. However, no suitable catalyst has yet been developed. Ru catalysts are known to be promoted by heavier alkali dopants. Instead of using heavy alkali metals, Li is herein shown to give the highest rate through surface polarisation despite its poorest electron donating ability. This exceptional promotion rate makes Ru-Li catalysts suitable for ammonia synthesis, which outclasses industrial Fe counterparts by at least 195 fold. Akin to enzyme catalysis, it is for the first time shown that Ru-Li catalysts hydrogenate end-on adsorbed N2 stabilized by Li+ on Ru terrace sites to ammonia in a stepwise manner, in contrast to typical N2 dissociation on stepped sites adopted by Ru-Cs counterparts, giving new insights in activating N2 by metallic catalysts.

[Regulatory effect of Shudihuang on expressions of BDNF/TrkB and NRG-3 in prefrontal cortex and striatum of ADHD model rats].

To observe the effect of Shudihuang on behaviors and expression of BDNF/TrkB and NRG-3 in prefrontal cortex and striatum of attention deficit hyperactivity disorder (ADHD) model rats. Thirty 4-week-old spontaneous hypertension rats (SHR) were randomly divided into model group, methylphenidate hydrochloride (MPH, 2 mg·kg⁻¹·d⁻¹) and Shudihuang group (2.4 g·kg⁻¹·d⁻¹). Another 10 Wistar-Kyoto (WKY) rats were selected as normal control group. The 0.5% CMC-Na solution was administered to model group and WKY rats (2 mL·kg⁻¹·d⁻¹). All of the rats were treated for 4 weeks. The open field test was performed at the 14th and 28th days after gavage, in order to evaluate the spontaneous and impulsive behaviors. Subsequently, gene and protein expressions of BDNF/TrkB and NRG-3 were tested by RT-qPCR and Western blot. Compared with model group, MPH and Shudihuang groups showed significant reduction in total distance, mean velocity and central distance in the open field test (P<0.05), and Shudihuang group displayed a shorter central distance than MPH group (P<0.05). RT-qPCR and Western blot analysis indicated that expressions of BDNF/TrkB and NRG-3 were lower in prefrontal cortex and striatum of SHR compared with WKY rats. Four weeks later after administration, both Shudihuang and MPH significantly elevated mRNA and protein expressions of BDNF/TrkB and NRG-3 (P<0.05).In conclusion, neurodevelopmental disorder mediated by BDNF/TrkB and NRG-3 was closely related with SHR rats' behaviors. Shudihuang may ameliorate the spontaneous and impulsive behaviors by up-regulating the expressions of BDNF/TrkB and NRG-3 and improving growth and maturation of neurons in SHR.

Multi-path photon-phonon converter in optomechanical system at single-quantum level.

Based on photon-phonon nonlinear interaction, a scheme of controllable photon-phonon converters is proposed at single-quantum level in a composed quadratically coupled optomechanical system. With the assistance of the mechanical oscillator, the Kerr nonlinear effect between photon and phonon is enhanced so that the single-photon state can be converted into the phonon state with high fidelity even under the current experimental condition that the single-photon coupling rate is much smaller than mechanical frequency (g ≪ ωm). The state transfer protocols and their transfer fidelity are discussed analytically and numerically. A multi-path photon-phonon converter is designed by combining the optomechanical system with low frequency resonators, which can be controlled by experimentally adjustable parameters. This work provides us a potential platform for quantum state transfer and quantum information.

[Expression of SSB following early myocardial ischemia in rats].

OBJECTIVE: To investigate the expression of Sjögren's syndrome antigen B (SSB) gene and SSB protein in the early ischemic myocardium in rats. METHODS: Adult healthy Sprague-Dawley rats were randomly divided into groups of operation [myocardial ischemia (MI) and non-ischemia (NI)], non-operation (NO) and sham-operation (SO) (n = 6 for MI and NI; n = 4 for NO and SO). According to time of ischemia, it was then divided into groups of 0 min, 15 min, 30 min, 60 min, 120 min, and 240 min. The expression of SSB gene in the myocardium was examined by real-time PCR, and the expression of SSB protein was examined by Western blot and immunofluorescence staining. RESULTS: The expressions of SSB gene was down-regulated at early stage of ischemia. There was significant difference between 0 min and 120 min at the level of expression of SSB gene in MI group, so did that between 120 min group and NO group (P < 0.05). The expression of SSB protein at 60 min after ischemia was significantly decreased compared with that in the group of 0 min (P < 0.05). The expression of SSB protein in NI groups was significantly higher than that in MI groups at the time of 60 min and 120 min after myocardial ischemia (P < 0.05). Additionally, the expression of SSB protein was mainly located in the myocardial nucleus, myocardial plasma, and plasma membrane of partial myocardiocytes according to the result of immunofluorescence staining. CONCLUSION: SSB may participate in pathophysiologic regulation process in myocardial cells at the early stage of myocardial ischemia in rats.

Inhibition of acid-sensing ion channels by amiloride protects rat articular chondrocytes from acid-induced apoptosis via a mitochondrial-mediated pathway.

A significant decrease in tissue pH or acidosis is a common feature of numerous diseases, including RA (rheumatoid arthritis). Cartilage homoeostasis is profoundly affected by local acidosis in the joints. The diuretic, amiloride, is neuroprotective in models of cerebral ischaemia, a property attributable to the inhibition of ASICs (acid-sensing ion channels) by the drug. However, little is known about the effect of amiloride on apoptosis induced by extracellular acid in articular chondrocytes. We have found that amiloride could restrain the acid-induced apoptosis of rat articular chondrocytes in vitro. Primary rat articular chondrocytes were isolated, cultured and induced to apoptose by exposure to extracellular solution (pH 6.0), while simultaneously treated with 50-200 µM amiloride. Apoptotic rate, mitochondrial function, levels of apoptosis-related gene Bcl-2 family mRNA and activity of caspase 3/9 in chondrocytes were examined. Amiloride inhibited chondrocyte apoptosis in a dose-dependent manner. Furthermore, amiloride partly restored the levels of mitochondrial membrane potential by regulation of Bcl-2 family gene mRNA expression, and activity of caspase 3/9 in chondrocytes induced by extracellular acid. Our results indicated that amiloride protected against acid-induced apoptosis in rat articular chondrocytes by increasing anti-apoptotic ability and down-regulation of pro-apoptotic factors, thus protecting mitochondrial function.

Relationship of abdominal aortic calcification with lumbar vertebral volumetric bone mineral density assessed by quantitative computed tomography in maintenance hemodialysis patients.

INTRODUCTION: This cross-sectional study aimed to investigate the relationship between abdominal aortic calcification (AAC), which is a marker of vascular calcification, and volumetric bone mineral density (vBMD) by quantitative computed tomography (QCT) in maintenance hemodialysis (MHD) patients. METHODS: All participants underwent lumbar vertebral vBMD measurement by QCT. Eight cross-sections were extracted sequentially and analyzed by ImageJ software to obtain the ratio of the calcified area to the abdominal aortic area (the calcification ratio). The AAC score was determined by the sum of the calcification ratios. The relationship between AAC and vBMD was analyzed using multivariate logistic regression. RESULTS: Ninety MHD patients (58.89% male) with a mean age of 63.43 (standard deviation [SD] = 13.20) years were included in the study. AAC was present (AAC score > 0) in 93.33% of the patients. The 75th percentile of the AAC score corresponding to 119 was used as the cutoff point between the mild and severe groups. After full adjustment in the logistic model, AAC was found to be inversely associated with vBMD (odds ratio [OR], 0.970; 95% confidence interval [CI], 0.944 to 0.996; P = 0.025), and patients with osteoporosis had a significantly higher risk of severe AAC than those with normal bone mass (OR, 14.498; 95% CI, 1.507 to 139.486; P = 0.021). The independent inverse association was still stable after adjusting for variables measured at different time periods and using different cutoff points of the AAC score. CONCLUSION: There was an independent inverse association between AAC and vBMD, and osteoporosis was significantly associated with severe AAC in patients with MHD.

[Expression of SSB gene in rats with early isehemic myocardium and its implications].

OBJECTIVE: To examine the expression of Sjögren's syndrome antigen B (SSB) gene in rats with early ischemic myocardium. METHODS: Adult healthy Sprague-Dawley rats were randomly divided into four groups (ischemia (MI), non-ischemia (NI), sham-operated (SO) and normal control (NO) groups). The expression of SSB and beta-actin gene in the myocardium was examined by real time PCR at 0 min, 5 min, 15 min, 30 min, 60 min, 120 min after ligation of the left anterior descending coronary artery (LAD). RESULTS: The expression of SSB gene was down-regulated after ischemia. Significantly lower expression of the gene in the rats with myocardial ischemia was found at 120 min after ligation compared with those before ligation and the control group at 120 min after ligation (P < 0.05 ). However, no significant differences were found between other groups (P > 0.05). CONCLUSION: SSB gene may be involved in the pathophysiologic regulating process in myocardial cells at the early stage of myocardial ischemia in rats.

[The expression of Basigin mRNA in early ischemic myocardium and non-ischemic myocardium].

OBJECTIVE: To investigate the expression of Basigin mRNA in early ischemic myocardium (EIM) and non-ischemic myocardium (NIM) in rat. METHODS: Real-time polymerase chain reaction (PCR) technique was applied for detecting Basigin mRNA and beta-actin expression in EIM and NIM at 0 min, 15 min, 30 min, and 60 min. RESULTS: No significant differences of the Basigin mRNA expression in EIM and NIM between 0 min and sham operation (SO) or non-operation group (P > 0.05) were observed. Basigin mRNA expression in EIM significantly decreased in 15 min, 30 min, and 60 min group compared with that of 0 min group, respectively (P < 0.001). However, we failed to find any significant difference in NIM and NO from 0 min to 60 min. Basigin mRNA expression in EIM decreased significantly compared with that of in NIM (P < 0.05) after myocardial ischemia for 30 min. CONCLUSION: Basigin was involved in myocardium pathophysiology process after myocardial ischemia for 30 min, indicating that Basigin may be identified as a predictor of early myocardial ischemia in forensic medicine.

Bone Turnover Markers and Bone Mineral Density to Predict Osteoporotic Fractures in Older Women: A Retrospective Comparative Study.

OBJECTIVE: To investigate the clinical significance of the detection of bone mineral density (BMD) and bone turnover markers (BTM) in older women with osteoporosis, and to compare their predictive power for osteoporotic fractures (OF). METHODS: In this retrospective study, 96 patients with OF and 107 patients with osteoporosis who were hospitalized in the Department of Orthopedics at the First Affiliated Hospital of Chengdu Medical College were examined from October 2017 to February 2019. All selected patients were divided into either the fracture group (96 cases, 47.3%) or the non-fracture group (107 cases, 52.7%). BMD was measured by dual-energy X-ray absorptiometry (DXA). BTM were detected by electrochemical luminescence: aminoterminal propeptide of type I procollagen (PINP), ß-cross-linked C-telopeptide of type I collagen (ß-CTX), and molecular fragment of osteocalcin N terminal (N-MID). Bone metabolism-related indicators were detected, including alkaline phosphatase (ALP), calcium (Ca), and phosphorus (P). Independent-samples t-tests were used to compare the measurement data between the two groups, one-way ANOVA to compare the gaps between groups, and binary logistic regression to analyze the correlation of BMD and BTM with OF. RESULTS: There were no significant differences in age, weight, height, body mass index, age, and time of menopause between the two groups. There were a total of 71 cases (35.0%) in group A (60-70 years), 80 cases (39.4%) in group B (71-80 years), and 52 cases (25.6%) in group C (81-90 years). The fracture group was compared with the non-fracture group for BMD in the lumbar (0.75 ± 0.05 vs 0.88 ± 0.13, 0.75 ± 0.16 vs 0.87 ± 0.09, 0.74 ± 0.21 vs 0.87 ± 0.12 g/cm2 ; P < 0.05), BMD in the hip (0.62 ± 0.16 vs 0.74 ± 0.14, 0.61 ± 0.15 vs 0.73 ± 0.0, 0.58 ± 0.13 vs 0.73 ± 0.08 g/cm2 ; P < 0.05), PINP (83.7 ± 5.7 vs 74.8 ± 5.0, 80.7 ± 4.1 vs 72.1 ± 5.1, 81.2 ± 7.0 vs 68.7 ± 6.3 ng/mL, P < 0.05), and ß-CTX (829.7 ± 91.5 vs 798.8 ± 52.2, 848.1 ± 71.2 vs 812.4 ± 79.0, 867.3 ± 53.1 vs 849.1 ± 67.2 pg./mL, P < 0.05). N-MID (19.0 ± 6.7 vs 21.3 ± 9.7, 16.2 ± 7.0 vs 18.0 ± 5.3 ng/mL, P < 0.05) in the fracture cases was lower than in the non-fracture cases for groups B and C, and there was statistical significance. Among the fracture cases, PINP in group A was higher than in group B and C, and ß-CTX in group C was higher than in group A and B (P < 0.05). There was no significant difference in the ALP, P, and Ca between the two groups (P > 0.05). Binary logistic regression analysis showed that for BMD in the lumbar and hip, ß-CTX and OF were significantly correlated (respectively, odds ratio [OR] = -4.182, 95% confidence interval [CI] 1.672-3.448; OR = 6.929, 95% CI 2.586-12.106; OR = 7.572, 95% CI 1.441-3.059), and the differences were statistically significant. PINP and N-MID were correlated with OF (respectively, OR = 4.213, 95% CI 0.978-1.005; OR = 2.510, 95% CI 1.070-1.134, P > 0.05), the difference was not statistically significant. CONCLUSION: Osteoporotic older women, with lower bone density and higher ß-CTX, are more likely to incur OF. ß-CTX is better than BMD at predicting OF and can help in its management and in implementing interventions in high-risk populations.

Phylogeography and paleodistribution models of a widespread birch (Betula platyphylla Suk.) across East Asia: Multiple refugia, multidirectional expansion, and heterogeneous genetic pattern.

Widespread tree species cover large geographical areas and play important roles in various vegetation types. Understanding how these species responded to historical climatic changes is important for understanding community assembly mechanisms with evolutionary and conservation implications. However, the location of refugial areas and postglacial history of widespread trees in East Asia remain poorly known. We combined microsatellite data (63 populations, 1756 individuals) and ecological niche modeling to examine the range-wide population diversity, genetic structure, and historical demography of a pioneer tree species, Asian white birch (Betula platyphylla Suk.) across East Asia. We found a north-to-south trend of declining genetic diversity and five clusters, corresponding to geographical regions. Different clusters were inferred to have diverged through Pleistocene climatic oscillations and have different expansion routes, leading to genetic admixture in some populations. Ecological niche models indicated that the distribution of B. platyphylla during the last glacial maximum still had a large latitude span with slight shifts toward southeast, and northern populations had more variable distribution ranges than those in the south during later climatic oscillations. Our results reflect the relatively stable distribution through the last glacial-interglacial cycles and recent multidirectional expansion of B. platyphylla, providing new hypotheses for the response pattern of widespread tree species to climate change. The gradual genetic pattern from northeast to southwest and alternative distribution dynamics possibly resulted from environmental differences caused by latitude and topographic heterogeneity.

Field-programmable beam reconfiguring based on digitally-controlled coding metasurface.

Digital phase shifters have been applied in traditional phased array antennas to realize beam steering. However, the phase shifter deals with the phase of the induced current; hence, it has to be in the path of each element of the antenna array, making the phased array antennas very expensive. Metamaterials and/or metasurfaces enable the direct modulation of electromagnetic waves by designing subwavelength structures, which opens a new way to control the beam scanning. Here, we present a direct digital mechanism to control the scattered electromagnetic waves using coding metasurface, in which each unit cell loads a pin diode to produce binary coding states of "1" and "0". Through data lines, the instant communications are established between the coding metasurface and the internal memory of field-programmable gate arrays (FPGA). Thus, we realize the digital modulation of electromagnetic waves, from which we present the field-programmable reflective antenna with good measurement performance. The proposed mechanism and functional device have great application potential in new-concept radar and communication systems.

Expression of basigin in the early phase of acute myocardial ischemia in rats.

Basigin may be involved in cardiovascular disease. In our previous study, suppression subtractive hybridization results indicated that basigin may be associated with the early phase of acute myocardial ischemia (AMI) within 1 h. However, little is known regarding the expression of basigin in the early phase of AMI. The aim of the present study was to evaluate the temporal and spatial expression patterns of basigin mRNA and protein levels in AMI in rats. We constructed an AMI model in rats that received left anterior descending coronary artery ligation for 0, 15, 30, 60, 120 or 240 min. Real­time quantitative PCR and in situ hybridization (ISH) were conducted to reveal the basigin mRNA levels in the early ischemic myocardium (EIM) and non­ischemic myocardium (NIM). The expression levels of basigin protein were detected using western blot analysis and immunohistochemistry. The expression levels of basigin mRNA and protein significantly changed in the EIM as early as 30 min from ischemia, and the changes continued to be present throughout the ischemic period (P<0.05). The expression levels of basigin mRNA were significantly reduced, whilst those of the protein underwent a significant ~2-fold increase in the EIM. However, there were no significant differences in the basigin mRNA or protein expression levels from 0­240 min in the NIM (P>0.05). We failed to detect a signal for basigin mRNA in the myocardium by ISH. Our findings indicated that basigin may be involved in acute myocardial ischemia following continual ischemia for >30 min.

Association between pri-miR-218 polymorphism and risk of hepatocellular carcinoma in a Han Chinese population.

MicroRNAs are noncoding RNA molecules of 18-25 nucleotides that regulate gene expression at the post-transcriptional level. The aim of this study was to investigate whether pri-miR-218 rs11134527 A/G polymorphism influences the risk of hepatocellular carcinoma (HCC) or not. pri-miR-218 rs11134527 A/G was genotyped in 302 HCC patients and 513 control subjects using the polymerase chain reaction-restriction fragment length polymorphism assay. The AG genotype of pri-miR-218 rs11134527 A/G was associated with family history (p=0.018, odds ratio [OR]=2.96, 95% confidence interval [CI]: 1.16-7.56) and elevated serum α-fetoprotein (serum alpha-fetoprotein [AFP]) levels (≥20 ng/mL; p=0.009, OR=1.92, 95% CI: 1.17-3.14) in HCC patients. These findings suggested that the AG genotype of pri-miR-218 rs11134527 might relate to genetic predisposition and be involved in regulating the expression of AFP in Chinese HCC patients.

CTLA4 and CD86 gene polymorphisms and susceptibility to chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) may be related to chronic inflammation and immune-mediated conditions, and its pathogenesis involves T-cell activation and proliferation. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and costimulatory molecules (CD80/CD86) genes are important mediators of T-cell activation in the immune response. The aim of this study was to investigate whether +2379G/C (rs17281995) and +1057G/A (rs1129055) in CD86 and -318C/T (rs5742909) and +49A/G (rs231775) in CTLA-4 genes single nucleotide polymorphisms (SNPs) are associated with COPD in a Chinese population. The four polymorphisms were identified in 396 COPD patients and 400 controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The frequency of the T allele of the -318C/T in CTLA-4 and the A allele of the +1057G/A in CD86 polymorphisms showed significant association with COPD when compared with controls (T allele: p < 0.0001; A allele: p = 0.009). Comparison of genotype frequencies showed that -318CT, +1057GA, and +1057AA genotype was overrepresented in the COPD group, respectively (-318CT: 50.8% vs 28.5%, p < 0.0001; +1057GA: 58.6% vs 54.2%, p = 0.002; +1057AA: 30.1% vs 25.8%, p = 0.002). However, we failed to find any association between the four SNPs and COPD when cases were classified by smoking status or clinical stages (p > 0.05). The results indicate that the polymorphisms of CTLA-4 (-318C/T) and CD86 (+1057G/A) may be important genetic factor associated with risk or protection for COPD in Chinese population.

IL-8 -251A/T polymorphism is associated with decreased cancer risk among population-based studies: evidence from a meta-analysis.

Growing evidence suggests that interleukin-8 (IL-8) play pivotal roles in the pathogenesis of cancer through the modulation of tumour immune response or enhanced angiogenesis. A single nucleotide polymorphism, -251A/T, has been identified in the promoter region of the IL-8 gene and has been shown to influence its production. Results from previous studies on the association of -251A/T polymorphism with different cancer types remained contradictory. To assess the effect of -251A/T of IL-8 on cancer susceptibility, we conducted a meta-analysis, up to May 2009, of 14,876 cases with different cancer types and 18,465 controls from 45 published case-control studies. Summary odds ratios and corresponding 95% confidence intervals (CIs) for IL-8 polymorphism and cancer were estimated using fixed- and random-effects models when appropriate. The AA/AT genotypes were associated with a significantly increased risk of nasopharyngeal carcinoma when compared with TT genotype (OR=1.48; 95% CI, 1.16-1.89). Moreover, significantly elevated risks were observed in 'other cancers', and also in African population when population is concerned. Interestingly, when stratified separately by population-based studies and hospital-based studies, significantly elevated risk was found among hospital-based studies (OR=1.21, 95% CI, 1.07-1.37), whereas significantly decreased risk was found among population-based studies (OR=0.90, 95% CI, 0.83-0.97). This meta-analysis shows that IL-8 -251A/T polymorphism may play a complex role in cancer development.

No association between vitamin D receptor polymorphisms and coronary artery disease in a Chinese population.

The clinical features suggest that genetic factors may have a strong influence on susceptibility to coronary artery disease (CAD). The aim of this study was to investigate the association between FokI (rs2228570) and BsmI (rs1544410) of the vitamin D receptor (VDR) gene polymorphisms and patients with CAD in a Chinese population. One hundred and fifty-two CAD patients and 212 healthy controls were genotyped for the FokI and BsmI polymorphisms in VDR gene using polymerase chain reaction-restriction fragment length polymorphism. No significant differences were observed in the genotype and allele frequencies of the FokI and BsmI polymorphisms between the cases and controls (For FokI: odds ratio = 1.11, 95% confidence interval 0.83-1.50; for BsmI: odds ratio = 0.74, 95% confidence interval 0.44-1.23). There was no significant difference in the genotype distribution or the allele frequencies of VDR FokI and BsmI between two groups in a Chinese population.