The complete chloroplast genome sequence of Ammodendron bifolium (Fabaceae), an endangered desert shrub from China.

Ammodendron bifolium, a rare deciduous shrub, is the only species of Ammodendron (Fabaceae) in China, which distributes in Huocheng county, Xinjiang. This study employed high-throughput sequencing technology to assemble the complete chloroplast genome sequence of A. bifolium. The entire length of chloroplast genome is 154,426 bp. It comprises 128 genes, which include 85 protein-coding genes, 35 tRNA genes, and 8 rRNA genes. The A. bifolium chloroplast genome has a GC content of 36.41%. Phylogenetic analysis strongly supported that A. bifolium is sister to the members of the Sophora genus. This study will provide the genetic information data for further phylogenetic studies of Ammodendron.

Ring Expansion toward Disila-carbocycles via Highly Selective C-Si/C-Si Bond Cross-Exchange.

Herein, we successfully inhibited the preferential homodimerization and C-Si/Si-H bond cross-exchange of benzosilacyclobutenes and monohydro-silacyclobutanes and achieved the first highly selective C-Si/C-Si bond cross-exchange reaction by deliberately tuning the Ni-catalytic system, which constitutes a powerful and atom-economical ring expansion method for preparing medium-sized cyclic compounds bearing two silicon atoms at the ring junction, which are otherwise inaccessible. The DFT calculation explicitly elucidated the pivotal role of Si-H bond at silacyclobutanes and the high ring strain of two substrates in realizing the two C-Si bonds cleavage and reformation in the catalytic cycle.

Origin of Octafluorocyclopentene Polyelectrophilicity.

Octafluorocyclopentene (OFCP) has found utility as a polyelectrophile in substitution cascades that form complex macrocyclic compounds. The Harran group synthesis of macrocyclic polypeptides depends on OFCP as a linker, combining with four different nucleophilic units of a polypeptide. We report a computational investigation of the origins of OFCP reactivity and a rationale for controlled mono-, di-, tri-, and tetrasubstitution of fluoride ions by heteroatomic nucleophiles. The roles of inductive, negative hyperconjugative, and resonance electron-donation by fluoride substituents are explored for the reaction of OFCP, less-fluorinated analogues, and common electrophilic alkenes with several different nucleophiles.

Catalytic Asymmetric Hydrogen Atom Transfer: Enantioselective Hydroamination of Alkenes.

We report a highly enantioselective radical-based hydroamination of enol esters with sulfonamides jointly catalyzed by an Ir photocatalyst, Brønsted base, and tetrapeptide thiol. This method is demonstrated for the formation of 23 protected ß-amino-alcohol products, achieving selectivities up to 97:3 er. The stereochemistry of the product is set through selective hydrogen atom transfer from the chiral thiol catalyst to a prochiral C-centered radical. Structure-selectivity relationships derived from structural variation of both the peptide catalyst and olefin substrate provide key insights into the development of an optimal catalyst. Experimental and computational mechanistic studies indicate that hydrogen-bonding, π-π stacking, and London dispersion interactions are contributing factors for substrate recognition and enantioinduction. These findings further the development of radical-based asymmetric catalysis and contribute to the understanding of the noncovalent interactions relevant to such transformations.

Cascade Synthesis of Fluorinated Spiroheterocyclic Scaffolding for Peptidic Macrobicycles.

Octafluorocyclopentene (OFCP) engages linear, unprotected peptides in polysubstitution cascades that generate complex fluorinated polycycles. The reactions occur in a single flask at 0-25 °C and require no catalysts or heavy metals. OFCP can directly polycyclize linear sequences using native functionality, or fluorospiroheterocyclic intermediates can be intercepted with exogenous nucleophiles. The latter tactic generates molecular hybrids composed of peptides, sugars, lipids, and heterocyclic components. The platform can create stereoisomers of both single- and double-looped macrocycles. Calculations indicate that the latter can mimic diverse protein surface loops. Subsets of the molecules have low energy conformers that shield the polar surface area through intramolecular hydrogen bonding. A significant fraction of OFCP-derived macrocycles tested show moderate to high passive permeability in parallel artificial membrane permeability assays.

Cross-attention multi-branch CNN using DCE-MRI to classify breast cancer molecular subtypes.

Purpose: The aim of this study is to improve the accuracy of classifying luminal or non-luminal subtypes of breast cancer by using computer algorithms based on DCE-MRI, and to validate the diagnostic efficacy of the model by considering the patient's age of menarche and nodule size. Methods: DCE-MRI images of patients with non-specific invasive breast cancer admitted to the Second Affiliated Hospital of Dalian Medical University were collected. There were 160 cases in total, with 84 cases of luminal type (luminal A and luminal B and 76 cases of non-luminal type (HER 2 overexpressing and triple negative). Patients were grouped according to thresholds of nodule sizes of 20 mm and age at menarche of 14 years. A cross-attention multi-branch net CAMBNET) was proposed based on the dataset to predict the molecular subtypes of breast cancer. Diagnostic performance was assessed by accuracy, sensitivity, specificity, F1 and area under the ROC curve (AUC). And the model is visualized with Grad-CAM. Results: Several classical deep learning models were included for diagnostic performance comparison. Using 5-fold cross-validation on the test dataset, all the results of CAMBNET are significantly higher than the compared deep learning models. The average prediction recall, accuracy, precision, and AUC for luminal and non-luminal types of the dataset were 89.11%, 88.44%, 88.52%, and 96.10%, respectively. For patients with tumor size <20 mm, the CAMBNET had AUC of 83.45% and ACC of 90.29% for detecting triple-negative breast cancer. When classifying luminal from non-luminal subtypes for patients with age at menarche years, our CAMBNET model achieved an ACC of 92.37%, precision of 92.42%, recall of 93.33%, F1of 92.33%, and AUC of 99.95%. Conclusions: The CAMBNET can be applied in molecular subtype classification of breasts. For patients with menarche at 14 years old, our model can yield more accurate results when classifying luminal and non-luminal subtypes. For patients with tumor sizes ≤20 mm, our model can yield more accurate result in detecting triple-negative breast cancer to improve patient prognosis and survival.

The effect of the COVID-19 pandemic on information disclosure: Evidence from China.

Using Chinese data, this study examines the effect of COVID-19 pandemic on tendencies and characteristics of information disclosure. Results show that, due to uncertainty caused by the pandemic, it is difficult to make earnings forecasts. Further, during the pandemic, forecast precision and timeliness decrease. The results remain unchanged under difference-in-difference (DiD) estimation. The findings of this paper extend existing studies on the economic consequences of COVID-19 pandemic and the influencing factors of information disclosure, providing implications for corporate managers, investors, and regulators.

Ebullition Controls on CH4 Emissions in an Urban, Eutrophic River: A Potential Time-Scale Bias in Determining the Aquatic CH4 Flux.

Rivers and streams contribute significant quantities of methane (CH4) to the atmosphere. However, there is a lack of CH4 flux and ebullitive (bubble) emission data from urban rivers, which might lead to large underestimations of global aquatic CH4 emissions. Here, we conducted high-frequency surveys using the boundary layer model (BLM) supplemented with floating chambers (FCs) and bubble traps to investigate the seasonal and diurnal variability in CH4 emissions in a eutrophic urban river and to evaluate whether the contribution of bubbles is important. We found that ebullition contributed nearly 99% of CH4 emissions and varied on hourly to seasonal time scales, ranging from 0.83 to 230 mmol m-2 d-1, although diffusive emissions and CH4 concentrations in bubbles did not exhibit temporal variability. Ebullitive CH4 emissions presented high temperature sensitivity (r = 0.6 and p < 0.01) in this urban river, and eutrophication might have triggered this high temperature sensitivity. The ebullitive CH4 flux is more likely to be underestimated at low temperatures because capturing the bubble flux is more difficult, given the low frequency of ebullition events. This study suggests that future ebullition measurements on longer time scales are needed to accurately quantify the CH4 budgets of eutrophic urban rivers.

Design and Implementation of a Real-Time Multi-Beam Sonar System Based on FPGA and DSP.

Aiming at addressing the contradiction between the high-speed real-time positioning and multi-channel signal processing in multi-beam sonar systems, in this work we present a real-time multi-beam sonar system based on a Field Programmable Gate Array (FPGA) and Digital Signal Processing (DSP) from two perspectives, i.e., hardware implementation and software optimization. In terms of hardware, an efficient high-voltage pulse transmitting module and a multi-channel data acquisition module with time versus gain (TVG) compensation with characteristics such as low noise and high phase amplitude consistency, are proposed. In terms of algorithms, we study three beamforming methods, namely delay-and-sum (D&S), direct-method (DM) and Chirp Zeta Transform (CZT). We compare the computational efficiency of DM and CZT in the digital domain. In terms of software, according to the transmission bandwidth of the Gigabit Ethernet and a serial rapid IO (SRIO) interface, the data transmission paths of the acquired data and the beam pattern between the FPGA, the DSP, and a personal computer (PC) are planned. A master-slave multi-core pipelined signal processing architecture is designed based on DSP, which enhances the data throughput of the signal processor by seven times as compared with that of the single-core operation. The experimental results reveal that the sound source level of the transmitting module is around 190.25 dB, the transmitting beam width is 64° × 64°, the background noise of the acquisition module is less than 4 µVrms, the amplitude consistency error of each channel is less than -6.55 dB, and the phase consistency error is less than 0.2°. It is noteworthy that the beam number of the sonar system is 90 × 90, the scanning angle interval is 0.33°, the working distance ranges from 5 m to 40 m, and the maximum distance resolution is 0.384 m. In the positioning experiment performed in this work; the 3-D real-time position of the baffle placed in the detection sector is realized. Please note that the maximum deviation of azimuth is 2°, the maximum deviation of elevation is 2.3°, and the maximum distance deviation is 0.379 m.

[Intestinal dysfunction of spinal cord injury treated with tongdu tiaoshen moxibustion: a randomized controlled trial].

OBJECTIVE: To compare the clinical effect on intestinal dysfunction of spinal cord injury (SCI) between the comprehensive therapy of tongdu tiaoshen moxibustion (moxibustion for opening the governor vessel and regulating the spirit) and rehabilitation training and the simple treatment with rehabilitation training. METHODS: A total of 60 patients with intestinal dysfunction of SCI were randomized into a comprehensive therapy group and a rehabilitation group, 30 cases in each one (3 cases were dropped out in each group). On the base of the routine western medicine treatment and rehabilitation training, the bowel training and rectal function training were provided, once a day in the rehabilitation group. In the comprehensive therapy group, on the base of the treatment as the rehabilitation group, the tongdu tiaoshen moxibustion was exerted at Yaoyangguan (GV 3), Mingmen (GV 4), Zhiyang (GV 9), Dazhui (GV 14) and Baihui (GV 20), etc, once a day, 30 min each time. In both groups, the treatment for 4 weeks was as one course and 3 courses of treatment were required. Separately, before treatment, after 4, 8 and 12 weeks of treatment, the scores of neurogenic bowel dysfunction (NBD) and World Health Organization quality of life scale (WHOQOL-BREF) were observed and the clinical effect was evaluated after 12 weeks of treatment. RESULTS: After treatment, the total effective rate was 88.9% (24/27) in the comprehensive therapy group, which was higher than 74.1% (20/27) in the rehabilitation group (P<0.05). After 4, 8 and 12 weeks of treatment, NBD scores were all reduced obviously as compared with those before treatment in the two groups (all P<0.01). After 8 and 12 weeks of treatment, NBD scores in the comprehensive therapy group were lower than the rehabilitation group (both P<0.05). After 4, 8 and 12 weeks of treatment, the scores of all of the domains (psychology, physiology, social relations and environment) in WHOQOL-BREF were higher than those before treatment in the two groups (all P<0.01). After 4 weeks of treatment, the scores in the psychology and physiology domains in the comprehensive therapy group were higher than the rehabilitation group (all P<0.05). After 8 and 12 weeks of treatment, the scores of all of the domains in the comprehensive therapy group were higher than the rehabilitation group (all P<0.05). CONCLUSION: The comprehensive treatment of tongdu tiaoshen moxibustion and rehabilitation training achieves the better effect on intestinal dysfunction of SCI than the simple rehabilitation training and greatly improves the quality of life in SCI patients.