Asymmetric Total Synthesis of Anti-HBV Drug Entecavir: Catalytic Strategies for the Stereospecific Construction of Densely Substituted Cyclopentene Cores.

We have successfully accomplished a catalytic asymmetric total synthesis of entecavir, a first-line antihepatitis B virus medication. The pivotal aspect of our strategy lies in the utilization of a Pd-catalyzed enyne borylative cyclization reaction, enabling the construction of a highly substituted cyclopentene scaffold with exceptional stereoselectivity. Additionally, we efficiently accessed the crucial 1,3-diol enyne system early in our synthetic route through a diarylprolinol organocatalyzed enantioselective cross-aldol reaction and Re-catalyzed allylic alcohol relocation. By strategically integrating these three catalytic protocols, we established a practical pathway for acquiring valuable densely heteroatom-substituted cyclopentene cores.

Comparing clinical outcomes of peroral endoscopic myotomy for achalasia between Eastern and Western countries: a systematic review and meta-analysis.

Peroral endoscopic myotomy (POEM) has revolutionized the therapeutic strategy for achalasia with promising results. We conducted this meta-analysis to compare clinical outcomes between Eastern and Western countries. A comprehensive literature search was conducted in PubMed, EMBASE, Web of Science and Cochrane Library databases to query for studies that assessed the efficacy of POEM for achalasia. All articles published from inception to December 31, 2021 were included. The primary outcome was the pooled clinical success rate. The secondary outcomes included the pooled technical success rate, incidence of adverse events, procedure time and hospital stay. Eighteen Eastern studies involving 5962 patients and 11 Western studies involving 1651 patients were included. The pooled clinical success rate and technical success rate for POEM was equal in the Eastern studies compared to Western studies. The pooled incidence of procedure adverse events for POEM was a little lower in the Eastern studies compared to Western studies (6.6% vs. 8.7%). Similarly, the incidence of reflux-related adverse events was lower in Eastern studies than that in Western studies. The pooled procedure time of POEM was shorter in Eastern studies compared to Western studies (61 minutes vs. 80 minutes), while the length of hospital stay was longer in Eastern studies compared to Western studies (5.8 days vs. 2.4 days). Overall, Eastern countries have the similar POEM outcomes compared to Western countries. However, Eastern countries still need to do more to reduce the length of hospital stay.

A systematic evaluation of methodological and reporting quality of meta-analysis published in the field of gastrointestinal endoscopy.

BACKGROUND: To evaluate the methodological and reporting quality of published meta-analyses (MAs) in four major gastrointestinal endoscopic journals, and identify the predicted factors for high quality. METHODS: A systematic search was performed in PubMed to identify MAs from 1, January, 2016 to 31, December, 2020 in four major gastrointestinal endoscopic journals (including Digestive Endoscopy, Gastrointestinal Endoscopy, Surgical Endoscopy, and Endoscopy). We collected the characteristics of MAs after filtering unqualified articles, and assessed methodological and reporting qualities for eligible articles by AMSTAR tool and PRISMA checklist, respectively. Logistic regression was used for identifying predictive factors for high quality. RESULTS: A total of 289 MAs were identified after screening by predefined inclusion and exclusion criteria. The scores (mean ± SD) of AMSTAR and PRISMA were 7.73 ± 1.11 and 22.90 ± 1.85, respectively. In PRISMA checklist, some items had less than 50% complete adherence, including item 2 (structured summary), items 5 (protocol and registration), items 12 and 19 (risk of bias in studies), item 27 (funding support). Item 1 (a priori design), item 4 (gray literature research), item 5 (list of included and excluded) were inferior to 50% adherence in AMSTAR tool. We found the predictive factors for high quality through logistic regression analysis: a priori design and funding support were associated with methodological quality. Protocol and registration influenced the methodological and reporting quality closely. CONCLUSION: In general, qualities on the methodology and the reporting of MAs published in the gastrointestinal endoscopic journals are good, but both of which still potentially need further improvement.

Grayscale Image Display Based on Nano-Polarizer Arrays.

Optical metasurfaces have shown unprecedented capabilities to control the two-dimensional distributions of phase, polarization, and intensity profiles of optical waves. Here, a TiO2 nanostructure functioning as a nano-polarizer was optimized considering that an anisotropic nanostructure is sensitive to the polarization states of incident light. We demonstrate two metasurfaces consisting of nano-polarizer arrays featured with different orientations, which can continuously manipulate the intensity distribution of the output light cell by cell according to Malus law and clearly display the detailed information of the target image. These metasurfaces have potential application in ultracompact displays, high-density optical information storage, and many other related polarization optics fields.

Endoscopic ultrasound-guided drainage of pelvic abscess: a systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: As an emerging minimally invasive technology, endoscopic ultrasound (EUS) has been reported to treat pelvic abscess instead of surgical or image-guided percutaneous drainage (PCD) under certain conditions. The aim of this study was to assess the efficacy and safety of EUS-guided drainage for patients with pelvic abscesses. METHODS: We conducted a comprehensive literature search on PubMed, Embase, Cochrane Library, and Web of Science databases (inception-March 2022). The main outcomes were technical success, clinical success, and complications. Comprehensive meta-analysis software was used to calculate the pooled event rate. RESULTS: Twelve studies containing 272 patients were included. These pelvic abscesses most frequently developed after abdominal and pelvic surgery (n = 180, 66.2%), inflammatory bowel disease (n = 32, 11.8%), and other inflammatory conditions. Respectively, the pooled technical and clinical success rate was 100% and 88.7% [95% confidence interval (CI): 83.8-92.2%, I2 = 1.0%, p < 0.001]. After excluding an individual study, the pooled rate of complications changed from 11.5% (95% CI: 7.4-17.4%, I2 = 38.8%, p < 0.001) to 8.2% (95% CI: 5.0-13.3%, I2 = 0, p < 0.001). CONCLUSIONS: EUS-guided drainage of the pelvic abscess was feasible, effective, and safe. Further randomized-controlled studies with large-sample sizes were required in the future.

High-Efficiency Polarization Multiplexing Metalenses.

The polarization multiplexing technique is a well-established method that improves the communication capacity of an optical system. In this paper, we designed orthogonal linear and circular polarization multiplexing metalens using a library of rectangle TiO2 nanostructures. The former can independently focus x- and y-linearly polarized incident lights to designed positions with a focusing efficiency of 53.81% and 51.56%, respectively, whereas the latter with two preset focal points can independently control left and right circularly polarized incident lights with a focusing efficiency of 42.45% and 42.46%, respectively. We also show that both metalenses can produce diffraction-limited focal spots for four polarization states with no obvious distortion, which opens up new applications in polarization imaging and polarization detection.

Controlled preparation and gas sensitive properties of two-dimensional and cubic structure ZnSnO3.

Two-dimensional (2D) ZnSnO3 is a promising candidate for future gas sensors due to its high chemical response and excellent electronic properties. However, the preparation of 2D ZnSnO3 nanosheets by utilizing soluble inorganic salts and nonorganic solvents remains a challenge. In this work, 2D ZnSnO3 was synthesized via a facile graphene oxide (GO)-assisted co-precipitation method, in which inorganic salts in the aqueous phase replaced metal organic salts in a non-aqueous system. Meanwhile, a "dissolution and recrystallization" mechanism was proposed to explain the transformation from 3D nanocubes to 2D nanosheets. In comparison, the 2D ZnSnO3 nanosheets showed a higher response to formaldehyde (HCHO) at low operating temperature (100 °C). The response (Ra/Rg) of the 2D ZnSnO3 sensor to 10 ppm HCHO was as high as 57, which was approximately 5 times the response of the ZnSnO3 nanocubes sensor. However, the ZnSnO3 nanocubes sensor showed better gas sensing performance to ethanol at high temperature (200 °C). Different gas-sensitive properties were attributed to the different gas diffusion and adsorption processes caused by the morphology and nanostructure. Moreover, both sensors could detect either 0.1 ppm HCHO or ethanol at their optimum operating temperature. This work presents a relatively economical method to prepare 2D compound metal oxides, provides a novel "dissolution and recrystallization" mechanism for 2D multi-metal oxide preparation, and sheds light on the great potential of high-efficiency HCHO and/or ethanol gas sensors.

PET/ZnO@MXene-Based Flexible Fabrics with Dual Piezoelectric Functions of Compression and Tension.

The traditional self-supported piezoelectric thin films prepared by filtration methods are limited in practical applications due to their poor tensile properties. The strategy of using flexible polyethylene terephthalate (PET) fabric as the flexible substrate is beneficial to enhancing the flexibility and stretchability of the flexible device, thus extending the applications of pressure sensors. In this work, a novel wearable pressure sensor is prepared, of which uniform and dense ZnO nanoarray-coated PET fabrics are covered by a two-dimensional MXene nanosheet. The ternary structure incorporates the advantages of the three components including the superior piezoelectric properties of ZnO nanorod arrays, the excellent flexibility of the PET substrate, and the outstanding conductivity of MXene, resulting in a novel wearable sensor with excellent pressure-sensitive properties. The PET/ZnO@MXene pressure sensor exhibits excellent sensing performance (S = 53.22 kPa-1), fast response/recovery speeds (150 ms and 100 ms), and superior flexural stability (over 30 cycles at 5% strain). The composite fabric also shows high sensitivity in both motion monitoring and physiological signal detection (e.g., device bending, elbow bending, finger bending, wrist pulse peaks, and sound signal discrimination). These findings provide insight into composite fabric-based pressure-sensitive materials, demonstrating the great significance and promising prospects in the field of flexible pressure sensing.

Efficient Achromatic Broadband Focusing and Polarization Manipulation of a Novel Designed Multifunctional Metasurface Zone Plate.

In this paper, comprehensively utilizing the diffraction theory and electromagnetic resonance effect is creatively employed to design a multifunctional metasurface zone plate (MMZP) and achieve the control of polarization states, while maintaining a broadband achromatic converging property in a near-IR region. The MMZP consists of several rings with fixed width and varying heights; each ring has a number of nanofins (usually called meta-atoms). The numerical simulation method is used to analyze the intensity distribution and polarization state of the emergent light, and the results show that the designed MMZP can realize the polarization manipulation while keeping the broadband in focus. For a specific design wavelength (0.7 µm), the incident light can be converted from left circularly polarized light to right circularly polarized light after passing through the MMZP, and the focusing efficiency reaches above 35%, which is more than twice as much as reported in the literature. Moreover, the achromatic broadband focusing property of the MMZP is independent with the polarization state of the incident light. This approach broadens degrees of freedom in micro-nano optical design, and is expected to find applications in multifunctional focusing devices and polarization imaging.