A model of hybrid speciation process drawn from three new poplar species originating from distant hybridization between sections.

Although numerous studies have been conducted on hybrid speciation, our understanding of this process remains limited. Through an 18-year systematic investigation of all taxa of Populus on the Qinghai-Tibet Plateau, we discovered three new taxa with clear characteristics of sect. Leucoides. Further evidence was gathered from morphology, whole-genome bioinformatics, biogeography, and breeding to demonstrate synthetically that they all originated from distant hybridization between sect. Leucoides and sect. Tacamahaca. P. gonggaensis originated from the hybridization of P. lasiocarpa with P. cathayana, P. butuoensis from the hybridization of P. wilsonii with P. szechuanica, and P. dafengensis from the hybridization of P. lasiocarpa with P. szechuanica. Due to heterosis, the three hybrid taxa possess greater ecological adaptability than their ancestral species. We propose a hybrid speciation process model that incorporates orthogonal, reverse, and backcrossing events. This model can adequately explain some crucial evolutionary concerns, such as the nuclear-cytoplasmic conflict on phylogeny and the extinction of ancestral species within the distribution range of hybrid species.

Lignans from the fruit of Schisandra glaucescens with antioxidant and neuroprotective properties.

Two rare 7,8-seco-lignans (1, 2), three new lignan glycosides (3, 4a, 4b), and 10 known lignans (5-14) were isolated from the fruit of Schisandra glaucescens Diels. The absolute configurations of 1 and 2 were determined by comparing their experimental and calculated electronic circular dichroism spectra. The molecular structures of the new compounds (3, 4a, and 4b), including their absolute configurations, were determined using various spectroscopic methods and hydrolysis reactions. The antioxidant activities of the isolated compounds were tested using 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays. Compounds 4, 7, 8, 10, 11, and 12 exhibited antioxidant activities of varying potential in both assays. Of these compounds, 7 showed the strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, with IC50 values of 15.7 (150 µM DPPH) and 34.6 µM (300 µM DPPH), respectively, and 4, 12, and 7 displayed higher total antioxidant activities than Trolox in the ferric reducing antioxidant power assay. The neuroprotective effects of these compounds against Aß25-35-induced cell death in SH-SY5Y cells were also investigated. Compounds 1, 2, 6, 7, 8, 11, and 12 exhibited statistically significant neuroprotective effects against Aß25-35-induced SH-SY5Y cell death compared with the group treated only with Aß25-35.

Neoadjuvant chemotherapy combined with immunotherapy versus neoadjuvant chemoradiotherapy in patients with locally advanced esophageal squamous cell carcinoma.

BACKGROUND: To date, few studies have compared effectiveness and survival rates of neoadjuvant chemotherapy combined with immunotherapy (NACI) and conventional neoadjuvant chemoradiotherapy (NCRT) in patients with locally advanced esophageal squamous cell carcinoma (ESCC). The present study was conducted to compare therapeutic response and survival between NACI and NCRT. METHODS: The study cohort comprised patients with locally advanced ESCC treated with either NACI or NCRT followed by surgery between June 2018 and March 2021. The 2 groups were compared for treatment response, 3-year overall survival (OS), and disease-free survival (DFS). Survival curves were created using the Kaplan-Meier method, differences were compared using the log-rank test, and potential imbalances were corrected for using the inverse probability of treatment weighting (IPTW) method. RESULTS: Among 202 patients with locally advanced ESCC, 81 received NACI and 121 received conventional NCRT. After IPTW adjustment, the R0 resection rate (85.2% vs 92.3%; P = .227) and the pathologic complete response (pCR) rate (27.5% vs 36.4%; P = .239) were comparable between the 2 groups. Nevertheless, patients who received NACI exhibited both a better 3-year OS rate (91.7% vs 79.8%; P = .032) and a better 3-year DFS rate (87.4% vs 72.8%; P = .039) compared with NCRT recipients. CONCLUSIONS: NACI has R0 resection and pCR rates comparable to those of NCRT and seems to be correlated with better prognosis than NCRT. NACI followed by surgery may be an effective treatment strategy for locally advanced ESCC.

Textile Bandwidth-Enhanced Polarization-Reconfigurable Half-Mode Substrate-Integrated Cavity Antenna.

A textile bandwidth-enhanced polarization-reconfigurable half-mode substrate-integrated cavity antenna was designed for wearable applications. A slot was cut out from the patch of a basic textile HMSIC antenna to excite two close resonances to form a wide -10 dB impedance band. The simulated axial ratio curve indicates the linear and circular polarization of the antenna radiation at different frequencies. Based on that, two sets of snap buttons were added at the radiation aperture to shift the -10 dB band. Therefore, a larger frequency range can be flexibly covered, and the polarization can be reconfigured at a fixed frequency by switching the state of snap buttons. According to the measured results on a fabricated prototype, the -10 dB impedance band of the proposed antenna can be reconfigured to cover 2.29~2.63 GHz (13.9% fractional bandwidth), and the circular/linear polarization radiation can be observed at 2.42 GHz with buttons OFF/ON. Additionally, simulations and measurements were carried out to validate the design and to study the effects of human body and bending conditions on the antenna performance.

The determining risk factors for treatment outcomes in patients with squamous cell carcinoma of the hard palate.

BACKGROUND: The determining risk factors for patients with squamous cell carcinoma of the hard palate are not well verified. METHODS: Medical records from our facility of all patients with squamous cell carcinoma of the hard palate receiving curative surgery between March 2003 and May 2009 were reviewed. RESULTS: Seventy-eight patients were enrolled in the study. The 5 year disease-free and overall survival rates were 49.8 and 49.7%, respectively. The 5 year disease-free and overall survival rates were statistically different between positive/close margins and negative margins (24.6% vs. 65.4%, P = 0.02; 20.1% vs. 63.1%, P = 0.001, respectively), with and without soft palate invasion (38.8% vs. 68.9%, P = 0.02; 27.4% vs. 77.5%, P = 0.001, respectively), and soft palate invasion patients with and without perineural invasion (10.4% vs. 52.8%, P = 0.02; 0% vs. 38.1%, P = 0.008, respectively). The rate of positive nodal metastasis for T3 and T4 tumors was 44%. For the tumor with soft palate invasion, the rate of positive nodal metastasis was 29%. After multivariate analyses, soft palate invasion and positive/close margins were the determining risk factors for disease-free and overall survival. CONCLUSIONS: Soft palate invasion and positive/close margins were the determining risk factors for disease-free and overall survival in patients with squamous cell carcinoma of the hard palate. Elective neck dissection is suggested for advanced primary tumors (T3 or T4) or tumors with soft palate invasion.

Neuroprotective lignans from the stems of Schisandra glaucescens.

Two new tetrahydrofuran lignans, schiglaucin A and B (1-2), together with eight known analogues (3-10), were isolated from the stems of Schisandra glaucescens Diels. Their structures were elucidated on the basis of spectroscopic techniques (HRESIMS, UV, IR, NMR, and CD experiments). All of the compounds were tested for their neuroprotective activities against H2O2- and CoCl2-induced cell injuries in SH-SY5Y cells, respectively. Compounds 1-10 showed significant neuroprotective effects against H2O2-induced SH-SY5Y cell death, while compounds 1-5 and 8-10 exhibited significant neuroprotective effects against CoCl2-induced SH-SY5Y cell injury.

Glutamine as a Potential Noninvasive Biomarker for Human Embryo Selection.

To determine whether glutamine consumption is associated with embryo quality and aneuploidy, a retrospective study was conducted in an in vitro fertilization center. Spent embryo culture media from patients undergoing assisted reproduction treatment and preimplantation genetic testing (PGT) were obtained on day 3 of in vitro culture. Embryo quality was assessed for cell number and fragmentation rate. PGT for aneuploidy was performed using whole genome amplification and DNA sequencing. Glutamine levels in spent embryo culture media were analyzed by gas chromatography-mass spectrometry. The results demonstrated that glutamine was a primary contributor to the classification of the good-quality and poor-quality embryos based on the orthogonal partial least-squares discriminant analysis model. Glutamine consumption in the poor-quality embryos was significantly higher than that in the good-quality embryos (P < 0.05). A significant increase in glutamine consumption was observed from aneuploid embryos compared with that from euploid embryos (P < 0.01). The Pearson correlation coefficients between embryo quality and glutamine consumption, and between aneuploidy and glutamine consumption, were 0.430 and 0.757, respectively. The area under the ROC curve was 0.938 (95% CI: 0.902-0.975) for identifying aneuploidy. Animal experiments demonstrate that increased glutamine consumption may be a compensatory mechanism to mitigate oxidative stress. Our data suggest that glutamine consumption is associated with embryo quality and aneuploidy. Glutamine may serve as a molecular indicator for embryo assessment and aneuploidy testing.

Possible correlation between selenoprotein W and myogenic regulatory factors in chicken embryonic myoblasts.

The biological function of selenium (Se) is mainly elicited through Se-containing proteins. Selenoprotein W (SelW), one member of the selenoprotein family, is essential for the normal function of the skeletal muscle system. To investigate the possible relationship of Se in the process of differentiation in chicken myoblasts and the expression of SelW, the cultured chicken embryonic myoblasts were incubated with sodium selenite at different concentrations for 72 h, and then the mRNA levels of SelW and myogenic regulatory factors (MRFs) in myoblasts were determined at 12, 24, 48, and 72 h, respectively. Furthermore, the correlation between SelW mRNA expression and MRF mRNA expression was assessed. The results showed that the sodium selenite medium enhanced the mRNA expression of SelW, Myf-5, MRF4, and myogenin in chicken myoblasts. The mRNA expression levels of MRFs were significantly correlated with those of SelW at 24, 48, and 72 h. These data demonstrate that Se is involved in the differentiation of chicken embryonic myoblasts, and SelW showed correlation with MRFs.

Schiglautone A, a new tricyclic triterpenoid with a unique 6/7/9-fused skeleton from the stems of Schisandra glaucescens.

Schiglautone A (1), a unique 6/7/9-fused tricyclic carbon backbone triterpenoid, was isolated from the stems of Schisandra glaucescens. Its structure was determined on the basis of spectroscopic analysis and single-crystal X-ray crystallography. A hypothetical biosynthetic pathway of 1 was postulated.

Arsenic trioxide induces the apoptosis in bone marrow mesenchymal stem cells by intracellular calcium signal and caspase-3 pathways.

It was previously reported that excessive arsenic trioxide would produce cardiovascular toxicity. Bone marrow mesenchymal stem cells (BMSCs) have been shown to play a supporting role in cardiovascular functions. The increasing apoptosis of BMSCs commonly would promote the development of cardiovascular diseases. Thus we hypothesize that arsenic trioxide caused apoptosis in BMSCs, which provided a better understanding of arsenic toxicity in hearts. The present study was designed to investigate the proapoptotic effects of arsenic trioxide on BMSCs and explore the mechanism underlying arsenic trioxide-induced BMSCs apoptosis. We demonstrate that arsenic trioxide significantly inhibited survival ratios of BMSCs in a concentration-dependent and time-dependent manner. The Annexin V/PI staining and terminal deoxynucleotidyl transferasemediated dUTP nick-end labelling (TUNEL) assay also showed that arsenic trioxide markedly induced the apoptosis of BMSCs. The caspase-3 activity was obviously enhanced in the presence of arsenic trioxide in a concentration-dependent manner in BMSCs. Additionally, arsenic trioxide caused the increase of intracellular free calcium ([Ca(2+)](i)) in rat BMSCs. BAPTA pretreatment may attenuate the apoptosis of BMSCs induced by arsenic trioxide. Taken together, arsenic trioxide could inhibit the proliferation and induce the apoptosis of BMSCs by modulating intracellular [Ca(2+)](i), and activating the caspase-3 activity.