160 research outputs found

    C-2/c-3 annulation and C-2 alkylation of indoles with 2-alkoxycyclopropanoate esters.

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    The annulation reaction between various indoles and 2-alkoxycyclopropanoate esters is reported. Both high efficiency and complete stereochemical control were observed in some cases with this annulation process. A single stereocenter on the cyclopropane controls the diastereoselective formation of up to four new stereocenters. A different reaction course was observed with 3-substituted indole substrates, and an intervening C-3 to C-2-migration process arose that gives synthetically useful C-2 alkylation indole products

    Synthesis and first X-ray structures of cobalt(II) and cobalt(III) complexes bearing 2,4-dioxo-alkanoic acid dialkylamide ligands

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    The aerobic oxidation of 5-hydroxy pentenes to trans-tetrahydrofurans (THFs), the Mukaiyama oxidation, has in recent years emerged as a powerful tool in synthetic chemistry. In this report we describe the first crystal structures of 2,4-dioxo-alkanoic acid dialkylamide complexes for both Co(II) and Co(III) salts. The Co(II) structures show an unprecedented arrangement of atoms, with a central Co(II)(H2O)6 flanked by two Co(II) atoms each coordinated with three anionic chelating ligands. The dimeric Co(III) structures show two anionic chelating ligands and bridging hydroxyl groups

    Misregulation of Alternative Splicing in a Mouse Model of Rett Syndrome

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    Mutations in the human MECP2 gene cause Rett syndrome (RTT), a severe neurodevelopmental disorder that predominantly affects girls. Despite decades of work, the molecular function of MeCP2 is not fully understood. Here we report a systematic identification of MeCP2-interacting proteins in the mouse brain. In addition to transcription regulators, we found that MeCP2 physically interacts with several modulators of RNA splicing, including LEDGF and DHX9. These interactions are disrupted by RTT causing mutations, suggesting that they may play a role in RTT pathogenesis. Consistent with the idea, deep RNA sequencing revealed misregulation of hundreds of splicing events in the cortex of Mecp2 knockout mice. To reveal the functional consequence of altered RNA splicing due to the loss of MeCP2, we focused on the regulation of the splicing of the flip/flop exon of Gria2 and other AMPAR genes. We found a significant splicing shift in the flip/flop exon toward the flop inclusion, leading to a faster decay in the AMPAR gated current and altered synaptic transmission. In summary, our study identified direct physical interaction between MeCP2 and splicing factors, a novel MeCP2 target gene, and established functional connection between a specific RNA splicing change and synaptic phenotypes in RTT mice. These results not only help our understanding of the molecular function of MeCP2, but also reveal potential drug targets for future therapies

    Impact of adjuvant gemcitabine containing chemotherapy following radical nephroureterectomy for patients with upper tract urothelial carcinoma: Results from a propensity-score matched cohort study

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    BACKGROUND: The evidence regarding perioperative adjuvant chemotherapy and personalized surveillance strategies for upper tract urothelial carcinoma is limited. OBJECTIVE: To evaluate whether adjuvant gemcitabine containing chemotherapy affects the oncological outcomes of advanced upper tract urothelial carcinoma (UTUC). METHODS: The CROES-UTUC registry is an observational, international, multi-center study on patients diagnosed with UTUC. Patient and disease characteristics from 2380 patients with UTUC were collected, and finally 738 patients were included in this analysis. The primary outcome of this study was recurrence-free survival. Propensity score matching was performed. Kaplan-Meier and multivariate Cox regression analyses were performed by stratifying patients according to the treatment of adjuvant chemotherapy. RESULTS: A total of 738 patients were included in this analysis, and 59 patients received adjuvant chemotherapy (AC), including 50 patients who received gemcitabine. A propensity score matching was performed, including 50 patients who received gemcitabine containing treatment and 50 patients without adjuvant chemotherapy. Disease recurrence occurred in 34.0% of patients. The recurrence rate in the AC group was 22.0%, which was significantly lower than the non-AC group (46.0%). Kaplan-Meier analyses also showed that AC was associated with a lower likelihood of tumor recurrence (p = 0.047). However, AC was not significantly associated with a higher overall survival (OS) (p = 0.908) and cancer-specific survival (CSS) (p = 0.979). Upon multivariate Cox regression analysis, AC was associated with a lower risk of tumor recurrence (HR = 0.297, p = 0.028). CONCLUSION: The present study confirms that adjuvant gemcitabine containing chemotherapy could decrease the risk of tumor recurrence in patients with locally advanced UTUC following nephroureterectomy. However, more studies are need to draw a clearer image of the value of this treatment method.STORZ to the Clinical Research Office of the Endourology Society (CROES

    Concomitant bladder tumor is a risk factor for bladder recurrence but not upper tract

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    Objective: To evaluate the clinical outcomes of UTUC patients with or without concurrent bladder tumor. Design, Setting, and Participants: The Clinical Research Office of the Endourology Society-Urothelial Carcinomas of the Upper Tract (CROES-UTUC) Registry included 1134 UTUC patients with or without concurrent bladder tumor treated between 2014 and 2019. Results: In 218 (19.2%) cases, concurrent bladder tumor was present, while in 916 (80.8%) patients, no bladder cancer was found. In the multivariable Cox regression analysis, concomitant bladder tumor (hazard ratio (HR) 1.562, 95% confidence interval (CI) 0.954-2.560, p = 0.076) indicated a trend associated with recurrence-free survival for UTUC. Further data dissection confirmed that concomitant bladder tumor is a risk factor of bladder recurrence (HR 1.874, 95% CI 1.104-3.183, p = 0.020) but not UTUC recurrence (HR 0.876, 95% CI 0.292-2.625, p = 0.812). Kidney-sparing surgery (KSS) (HR 3.940, 95% CI 1.352-11.486, p = 0.012), pathological T staging >= pT2 (HR 2.840, 95% 1.039-7.763, p = 0.042) were significantly associated with UTUC recurrence. KSS does not affect bladder recurrence (HR 0.619, 95% CI 0.242-1.580, p = 0.315). A limitation is the retrospective nature of the present study analysis. Conclusions: The presence of concomitant bladder tumor does not increase risk of UTUC recurrence, but it results in an increased risk of bladder recurrence. KSS does not affect bladder recurrence and can still be considered in patients with concomitant bladder tumor

    Impact of previous malignancy at diagnosis on oncological outcomes of upper tract urothelial carcinoma

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    BACKGROUND: The evidence of prognostic factors and individualized surveillance strategies for upper tract urothelial carcinoma are still weak. OBJECTIVES: To evaluate whether the history of previous malignancy (HPM) affects the oncological outcomes of upper tract urothelial carcinoma (UTUC). METHODS: The CROES-UTUC registry is an international, observational, multicenter cohort study on patients diagnosed with UTUC. Patient and disease characteristics from 2380 patients with UTUC were collected. The primary outcome of this study was recurrence-free survival. Kaplan-Meier and multivariate Cox regression analyses were performed by stratifying patients according to their HPM. RESULTS: A total of 996 patients were included in this study. With a median recurrence-free survival time of 7.2 months and a median follow-up time of 9.2 months, 19.5% of patients had disease recurrence. The recurrence-free survival rate in the HPM group was 75.7%, which was significantly lower than non-HPM group (82.7%, P = 0.012). Kaplan-Meier analyses also showed that HPM could increase the risk of upper tract recurrence (P = 0.048). Furthermore, patients with a history of non-urothelial cancers had a higher risk of intravesical recurrence (P = 0.003), and patients with a history of urothelial cancers had a higher risk of upper tract recurrence (P = 0.015). Upon multivariate Cox regression analysis, the history of non-urothelial cancer was a risk factor for intravesical recurrence (P = 0.004), and the history of urothelial cancer was a risk factor for upper tract recurrence (P = 0.006). CONCLUSION: Both previous non-urothelial and urothelial malignancy could increase the risk of tumor recurrence. But different cancer types may increase different sites' risk of tumor recurrence for patients with UTUC. According to present study, more personalized follow-up plans and active treatment strategies should be considered for UTUC patients

    A proof-of-concept study on endoscopic ultrasound-guided biopsy of detrusor muscle in porcine bladders

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    IntroductionConventionally, we rely on transurethral resection of bladder tumour (TURBT) for local staging of muscle-invasive bladder cancer (MIBC). However, the procedure is limited by its staging inaccuracy which may delay the definitive treatment of MIBC.MethodsWe conducted a proof-of concept study on endoscopic ultrasound (EUS)-guided biopsy of detrusor muscle in porcine bladders. Five porcine bladders were used in this experiment. Upon EUS, four layers of tissue including the mucosa (hypoechoic), submucosa (hyperechoic), detrusor muscle (hypoechoic) and serosa (hyperechoic) could be identified.ResultsA total of 37 EUS-guided biopsies were taken from 15 sites (three sites per bladder), and the mean number of biopsies taken from each site was 2.47±0.64. Among the 37 biopsies, 30 of them (81.1%) obtained detrusor muscle in the biopsy specimen. For the per biopsy site analysis, detrusor muscle was obtained in 73.3% if only one biopsy was taken, and 100% if two or more biopsies were taken from the same biopsy site. Overall, detrusor muscle was successfully obtained from all 15 biopsy sites (100%). No bladder perforation was observed throughout all biopsy processes.ConclusionEUS-guided biopsy of the detrusor muscle could be performed during the initial cystoscopy session, thus expediting the histological diagnosis and subsequent treatment of MIBC

    WHTO: A methodology of calculating the energy extraction of wave energy convertors based on wave height reduction

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordWave energy has significant worldwide exploitable resource and its exploitation has attracted renewable energy investigator’ attention. Great progress on calculating device performance has been made by means of theoretical, numerical and model tests. This paper presents a method of calculating the energy extraction of a wave energy converter (WEC) based on Wave Height Take-off (WHTO). The method provides a means to improve the capture efficiency of designs, including demonstrating how well different kinds of WEC are optimized for certain wave conditions. Numerical simulations of a heaving buoy and a bottom-hinged pendulum in a 2D wave flume with different damping types (linear and nonlinear) are presented. The results show that the difference between the calculated energy extraction from the wave height reduction and from the model power take-off (PTO) was not significant in a 2D flume. Physical model tests were conducted using a simplified PTO consisting of a system of lifting weights, used to measure the energy extraction directly. Based on both numerical and physical model analyses, the article defines WHTO, which is equivalent to energy extracted by PTO, but determined without taking direct measurements. This paper aims to promote and validate the concept of the WHTO.National Natural Science Foundation of ChinaShandong Provincial Natural Science FoundationSpecial Project for Marine Renewable EnergyQingdao Municipal Science and Technology ProgramChina Scholarship Counci

    Baichuan 2: Open Large-scale Language Models

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    Large language models (LLMs) have demonstrated remarkable performance on a variety of natural language tasks based on just a few examples of natural language instructions, reducing the need for extensive feature engineering. However, most powerful LLMs are closed-source or limited in their capability for languages other than English. In this technical report, we present Baichuan 2, a series of large-scale multilingual language models containing 7 billion and 13 billion parameters, trained from scratch, on 2.6 trillion tokens. Baichuan 2 matches or outperforms other open-source models of similar size on public benchmarks like MMLU, CMMLU, GSM8K, and HumanEval. Furthermore, Baichuan 2 excels in vertical domains such as medicine and law. We will release all pre-training model checkpoints to benefit the research community in better understanding the training dynamics of Baichuan 2.Comment: Baichuan 2 technical report. Github: https://github.com/baichuan-inc/Baichuan
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