Publications by authors named "Zhi-cheng Huang"

Article Synopsis
  • Scientists are using a special tool called paired Cas9 nickases (Cas9n) to edit genes, which helps reduce mistakes.
  • They found that a protein called TREX2 can help improve the success of this gene editing when they deal with tricky parts called 3'-overhanging ends.
  • By teaming up TREX2 with Cas9n, they made the editing process safer and more efficient, making it easier to change genes for various purposes.
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Suspended sediment concentration (c) has been considered a critical environmental factor in reef habitats; however, the values and variations of c are not evident in a unique reef mainly created by crustose coralline algal concretions compared to abundant studies in coral reefs. The results of real-time and long-term monitoring of waves and c over the intertidal algal reef are reported because of the construction of an offshore industrial harbor near the reef. The real-time monitoring systems were based on techniques, including optical backscatter sensors (OBSs) for measuring c, pressure sensors for measuring waves, data loggers, and wireless networks for data transmission.

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Background: Due to post-cleavage residence of the Cas9-sgRNA complex at its target, Cas9-induced DNA double-strand breaks (DSBs) have to be exposed to engage DSB repair pathways. Target interaction of Cas9-sgRNA determines its target binding affinity and modulates its post-cleavage target residence duration and exposure of Cas9-induced DSBs. This exposure, via different mechanisms, may initiate variable DNA damage responses, influencing DSB repair pathway choices and contributing to mutational heterogeneity in genome editing.

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Article Synopsis
  • Analysis of human cancer genomes indicates that BRCA1-deficient tumors have distinctive mutation patterns, but the reasons behind these patterns are still unclear.
  • The study found that one-ended DNA double strand breaks (DSBs) created by CRISPR/Cas9 are more likely to cause genetic abnormalities in BRCA1-deficient cells than in normal cells, as they rely on DNA replication for repair.
  • Faulty repair of these one-ended DSBs leads to specific mutations commonly seen in BRCA1-deficient tumors, suggesting that DNA nicks play a significant role in the cancer mutations associated with BRCA1 loss.
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The spiro scaffold chiral organocatalyst of 3,2'-pyrrolidinyl spiro-oxindole amine was successfully prepared from racemic spiro-oxindole amine using l-menthol as a chiral pool in 4 steps in 28%-40% overall yields with at least 99% ee in scale-up preparation, and its catalytic activity was evaluated in the enantioselective aldol condensation between 3-(3-hydroxy-1-pyrazol-1-yl)-oxindole and paraformaldehyde. The spiro organocatalyst showed superior catalytic activity and selectivity compared with its counterparts, and most substrates offered good to excellent results with up to 96% yield in 96% ee.

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A new and crucial synthon of 3-((diphenylmethylene)-amino)-oxindole was designed and synthesized, for which an organocatalytic and enantioselective Michael/cyclization reaction with a terminal vinyl ketone catalyzed by a cinchona base was disclosed. A wide variety (28 examples) of almost all new chiral spiro[oxindol-3,2'-pyrrols] were prepared in excellent yields (up to 99%) with excellent enantioselectivities (95-99% ee), of which a typical chiral spiro product was further reduced to chiral spiro[oxindole-3,2'-pyrrolidine].

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A new base promoted Michael-Michael domino cycloaddition between isoindigos and α-alkylidene succinimides has been developed for highly efficient and one-step convenient preparation of highly steric bispiroxindoles with two adjacent quaternary carbon centers and four consecutive cycles in excellent yields (up to 96%) and diastereoselectivities (up to >20 : 1) under mild conditions within a few minutes. A series of bisprooxindoles were obtained and the synthetic potential of the protocol was evaluated in a scale-up preparation.

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A cinchona alkaloid squaramide promoted enantioselective [4+2] cyclization between hydroxymaleimides and ortho-hydroxyphenyl p-QMs has been disclosed, and a wide range of chiral hemiketals containing chromane and succinimide frameworks with two adjacent quaternary stereogenic centers have been prepared for the first time with excellent results (up to 99% yield, up to 99 : 1 dr, up to >99% ee) under mild conditions.

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A new enantioselective Michael addition between 3-(3-hydroxy-1-pyrazol-1-yl)oxindole, a new synthon generated from isatin ,-cyclic azomethine imine 1,3-dipole, and β-nitrostyrene has been disclosed. A series of chiral 3-(3-oxo-2,3-dihydro-1-pyrazol-1-yl) disubstituted oxindoles were obtained in excellent results (up to 97% yield, up to 94% ee) with moderate to good diastereoselectivities (up to 4.3:1 dr).

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Article Synopsis
  • * A theoretical model using the transfer matrix method was developed to predict the transmission spectrum and numerical calculations revealed that resonant peaks shift to higher frequencies as interfacial stiffness increases.
  • * Experimental results from bonding specimens with varied properties corroborated the theoretical predictions regarding the shift directions and distances of the transmission peaks, although the theory of "starting points" was not fully validated.
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Human Nestin (hNestin) has been found to express in melanoma, and its expression is positively correlated with the advanced stage of melanoma. However, the precise role of hNestin in the development of melanoma has not been fully understood. The present study aimed to explore the role of hNestin in the proliferation and invasion of melanoma cells.

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Objective: To investigate the influence of the time interval from the end of semen processing to artificial intrauterine in semination with husband's sperm (AIH-IUI) on the rate of clinical pregnancy.

Methods: This study involved 191 AIH-IUI cycles with the same ovulation induction protocol. After Percoll density gradient centrifugation, we divided the sperm into four groups based on the incubation time: 0-19, 20-39, 40-59, and 60-80 min, and again into another four groups according to the total progressively motile sperm count (TPMC): (0-9), (10-20), (21-30), and > 30 x 10(6).

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Herpes simplex virus type 2 (HSV-2) is the major cause of genital herpes in humans. The glycoprotein D of HSV-2 (gD2) is a promising subunit vaccine candidate for the treatment of genital herpes. The aim of the present study was to express a biologically active recombinant gD2 in eukaryotic baculovirus system in quantities sufficient for further studies.

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Objective: To develop a rapid and simple multiplex polymerase chain reaction (PCR) method which discriminates extended-spectrum beta-lactamases (ESBLs) genes in sporadic Shigella isolates from 1998 to 2007 in Hangzhou city, China.

Methods: After ESBLs screening according to the Clinical and Laboratory Standards Institute (CLSI) method, CTX-M, TEM, SHV and OXA-1 encoding genes were detected by using a multiplex PCR method, and the results were verified by 8 single gene PCR amplification.

Results: Seventeen isolates harbored ESBLs genes among 195 Shigella isolates (8.

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Article Synopsis
  • - The study aimed to analyze fluoroquinolone-resistant Shigella strains in the Hangzhou area of China, focusing on the role of specific resistance genes (qnr and aac(6')-Ib-cr) in sporadic shigellosis cases from 1998 to 2007.
  • - Researchers tested 202 Shigella strains and found that while all S. sonnei strains were susceptible to fluoroquinolones, 15 S. flexneri strains exhibited resistance linked to mutations in the gyrA and parC genes, as well as the presence of the qnrS and aac(6')-Ib-cr genes.
  • - The study highlighted that specific mutations in the gyrA and parC
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Objective: To prepare the armored RNA containing M gene of influenza H3N2.

Methods: The vector pAR-1 was constructed from expression vector pET30b in which the bacteriophage MS2 DNA fragment, containing the genes for maturase and coat protein and the pac site, was inserted. The M gene fragment of influenza A was inserted into the HindIII site downstream of the pac site on the pAR-1, which formed a new recombinant plasmid pAR-2.

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The common respiratory viruses, including influenza A, influenza B, and newly emerging severe acute respiratory syndrome (SARS) viruses, may cause similar clinical symptoms. Therefore, differential diagnosis of these virus pathogens is frequently required for single clinical samples. In addition, there is an urgent need for noninfectious and stable RNA standards and controls for multivirus detection.

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Article Synopsis
  • The study aimed to detect SARS-CoV RNA using various RT-PCR techniques to improve test reliability and sensitivity.
  • It involved testing oropharyngeal swabs from probable and suspect SARS patients, with a successful sequencing of positive samples.
  • Results showed that modified nested real-time RT-PCR was more sensitive than standard methods, detecting lower levels of RNA more effectively.
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