PAM-independent ultra-specific activation of CRISPR-Cas12a via sticky-end dsDNA.

Although CRISPR-Cas12a [clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 12a] combining pre-amplification technology has the advantage of high sensitivity in biosensing, its generality and specificity are insufficient, which greatly restrains its application range. Here, we discovered a new targeting substrate for LbaCas12a (Lachnospiraceae bacterium Cas12a), namely double-stranded DNA (dsDNA) with a sticky-end region (PAM-SE+ dsDNA). We discovered that CRISPR-Cas12a had special enzymatic properties for this substrate DNA, including the ability to recognize and cleave it without needing a protospacer adjacent motif (PAM) sequence and a high sensitivity to single-base mismatches in that substrate. Further mechanism studies revealed that guide RNA (gRNA) formed a triple-stranded flap structure with the substrate dsDNA. We also discovered the property of low-temperature activation of CRISPR-Cas12a and, by coupling with the unique DNA hybridization kinetics at low temperature, we constructed a complete workflow for low-abundance point mutation detection in real samples, which was fast, convenient and free of single-stranded DNA (ssDNA) transformation. The detection limits were 0.005-0.01% for synthesized strands and 0.01-0.05% for plasmid genomic DNA, and the mutation abundances provided by our system for 28 clinical samples were in accordance with next-generation sequencing results. We believe that our work not only reveals novel information about the target recognition mechanism of the CRISPR-Cas12a system, but also greatly broadens its application scenarios.

[Preparation and effectiveness evaluation of placebo of Jiawei Ermiao Granules].

This study explored the preparation process of the placebo of Jiawei Ermiao Granules and evaluated the placebo effect, aiming to provide qualified placebo samples for clinical trials of Jiawei Ermiao Granules and a reference for the preparation and quality evaluation of placebos of traditional Chinese medicine granules. On the basis of the comprehensive analysis results of Jiawei Ermiao Granules, the orthogonal experiment was conducted to optimize the flavoring agents and colorants. After manual evaluation, the placebo formula was determined as dextrin 10 g, Codonopsis Radix extract 5.0 g, bitter melon extract 1.6 g, Mume Fructus extract 0.3 g, stevioside 0.1 g, sucrose octaacetate 0.004 g, indigo 0.004 g, lemon yellow 0.003 1 g, sunset yellow 0.001 8 g, bitter tea powder 0.001 8 g, caramel 0.001 3 g. Pilot trials were conducted on the placebo formula. The simulation effect of placebo was evaluated independently and comparatively, and the objectively evaluated by electronic nose and electronic tongue. The results showed that the independent manual evaluation of the placebo formula had higher error rate, and the placebo and Jiawei Ermiao Granules showed the similarity of 99.61% in the comparative manual evaluation. The smell similarity between the placebo and Jiawei Ermiao Granules was 99.19%, and the electronic tongue test showed little difference in the taste. In conclusion, the placebo prepared in this study shows a high similarity to Jiawei Ermiao Granules, which is not easy to break the blindness when being applied to clinical trials. This study provides a reference for the preparation and quality evaluation and promotes the large-scale production of placebos of traditional Chinese medicine granules, playing a role in improving the persuasiveness and acceptance of the efficacy of traditional Chinese medicines.

Sodium butyrate induces ferroptosis in endometrial cancer cells via the RBM3/SLC7A11 axis.

Ferroptosis is a form of programmed cell death with important biological functions in the progression of various diseases, and targeting ferroptosis is a new tumor treatment strategy. Studies have shown that sodium butyrate plays a tumor-suppressing role in the progression of various tumors, however, the mechanism of NaBu in endometrial cancer is unclear. Cell viability, clone formation, proliferation, migration, invasion abilities and cell cycle distribution were assessed by CCK8 assay, Clone formation ability assay, EdU incorporation, Transwell chambers and flow cytometry. The level of ferroptosis was assayed by the levels of ROS and lipid peroxidation, the ratio of GSH/GSSG and the morphology of mitochondria. Molecular mechanisms were explored by metabolome, transcriptome, RNA-pulldown and mass spectrometry. The in-vivo mechanism was validated using subcutaneous xenograft model. In this study, NaBu was identified to inhibit the progression of endometrial cancer in vitro and in vivo. Mechanistically, RBM3 has a binding relationship with SLC7A11 mRNA. NaBu indirectly downregulates the expression of SLC7A11 by promoting the expression of RBM3, thereby promoting ferroptosis in endometrial cancer cells. In conclusion, Sodium butyrate can promote the expression of RBM3 and indirectly downregulate the expression of SLC7A11 to stimulate ferroptosis, which may be a promising cancer treatment strategy.

Transcriptional level of inflammation markers associates with short-term brain structural changes in first-episode schizophrenia.

BACKGROUND: Inflammation has been implicated in the pathology of schizophrenia and may cause neuronal cell death and dendrite loss. Neuroimaging studies have highlighted longitudinal brain structural changes in patients with schizophrenia, yet it is unclear whether this is related to inflammation. We aim to address this question, by relating brain structural changes with the transcriptional profile of inflammation markers in the early stage of schizophrenia. METHODS: Thirty-eight patients with first-episode schizophrenia and 51 healthy controls were included. High-resolution T1-weighted magnetic resonance imaging (MRI) and clinical assessments were performed at baseline and 2 ~ 6 months follow-up for all subjects. Changes in the brain structure were analyzed using surface-based morphological analysis and correlated with the expression of immune cells-related gene sets of interest reported by previous reviews. Transcriptional data were retrieved from the Allen Human Brain Atlas. Furthermore, we examined the brain structural changes and peripheral inflammation markers in association with behavioral symptoms and cognitive functioning in patients. RESULTS: Patients exhibited accelerated cortical thickness decrease in the left frontal cortices, less decrease or an increase in the superior parietal lobule and right lateral occipital lobe, and increased volume in the bilateral pallidum, compared with controls. Changes in cortical thickness correlated with the transcriptional level of monocyte across cortical regions in patients (r = 0.54, p < 0.01), but not in controls (r = - 0.05, p = 0.76). In addition, cortical thickness change in the left superior parietal lobule positively correlated with changes in digital span-backward test scores in patients. CONCLUSIONS: Patients with schizophrenia exhibit regional-specific cortical thickness changes in the prefrontal and parietooccipital cortices, which is related to their cognitive impairment. Inflammation may be an important factor contributing to cortical thinning in first-episode schizophrenia. Our findings suggest that the immunity-brain-behavior association may play a crucial role in the pathogenesis of schizophrenia.

Differential expression of diacylglycerol kinase ζ is involved in inferior parietal lobule-related dysfunction in schizophrenia with cognitive impairments.

BACKGROUND: Cognitive impairment is the main factor in the poor prognosis of schizophrenia, but its mechanism remains unclear. The inferior parietal lobule (IPL) is related to various clinical symptoms and cognitive impairment in schizophrenia. We aimed to explore the relationship between IPL-related functions and cognitive impairment in schizophrenia. METHODS: 136 schizophrenia patients and 146 demographically matched healthy controls were enrolled for a cross-sectional study. High-spatial-resolution structural and resting-state functional images were acquired to demonstrate the alternations of brain structure and function. At the same time, the digit span and digit symbol coding tasks of the Chinese Wechsler Adult Intelligence Test Revised (WAIS-RC) were utilized in assessing the subjects' cognitive function. Patients were divided into cognitive impairment and normal cognitive groups according to their cognitive score and then compared whether there were differences between the three groups in fractional amplitude of low-frequency fluctuation (fALFF). In addition, we did a correlation analysis between cognitive function and the fALFF for the left IPL of patients and healthy controls. Based on the Allen Human Brain Atlas, we obtained genes expressed in the left IPL, which were then intersected with the transcriptome-wide association study results and differentially expressed genes in schizophrenia. RESULTS: Grouping of patients by the backward digit span task and the digit symbol coding task showed differences in fALFF values between healthy controls and cognitive impairment patients (P < 0.05). We found a negative correlation between the backward digit span task score and fALFF of the left IPL in healthy controls (r = - 0.388, P = 0.003), which was not seen in patients (r = 0.203, P = 0.020). In addition, none of the other analyses were statistically significant (P > 0.017). In addition, we found that diacylglycerol kinase ζ (DGKζ) is differentially expressed in the left IPL and associated with schizophrenia. CONCLUSION: Our study demonstrates that the left IPL plays a vital role in cognitive impairment in schizophrenia. DGKζ may act as an essential regulator in the left IPL of schizophrenia patients with cognitive impairment.

Gene signature and prognostic value of ubiquitination-related genes in endometrial cancer.

Protein ubiquitination is closely related to tumor occurrence and development. The specific role of ubiquitination in endometrial cancer remains largely unclear. Therefore, we constructed a novel endometrial cancer prognostic model based on ubiquitination-related genes. We extracted the expression matrices of ubiquitination-related genes from the Cancer Genome Atlas database, upon which we performed univariate Cox regression and least absolute shrinkage and selection operator (LASSO) regression analyses to obtain 22 ubiquitination-related genes for the construction of the prognostic model. Survival, regression, clinical correlation, and principal component analyses were performed to assess the performance of the model. Drug sensitivity analysis was performed based on these ubiquitination-related genes. Finally, a prognostic nomogram was constructed based on the prognostic model to quantify patient outcomes. Survival, regression, clinical correlation, and principal component analyses revealed that the performance of the prognostic model was satisfactory. Drug sensitivity analysis provided a potential direction for the treatment of endometrial cancer. The prognostic nomogram could be used to effectively estimate the survival rate of patients with endometrial cancer. In summary, we constructed a new endometrial cancer prognostic model and identified 5 differentially expressed, prognosis-associated, ubiquitination-related genes. These 5 genes are potential diagnostic and treatment targets for endometrial cancer.

Transmission Dynamics and Effectiveness of Control Measures during COVID-19 Surge, Taiwan, April-August 2021.

An unprecedented surge of COVID-19 cases in Taiwan in May 2021 led the government to implement strict nationwide control measures beginning May 15. During the surge, the government was able to bring the epidemic under control without a complete lockdown despite the cumulative case count reaching >14,400 and >780 deaths. We investigated the effectiveness of the public health and social measures instituted by the Taiwan government by quantifying the change in the effective reproduction number, which is a summary measure of the ability of the pathogen to spread through the population. The control measures that were instituted reduced the effective reproduction number from 2.0-3.3 to 0.6-0.7. This decrease was correlated with changes in mobility patterns in Taiwan, demonstrating that public compliance, active case finding, and contact tracing were effective measures in preventing further spread of the disease.

The correlation between dynamic functional architecture and response to electroconvulsive therapy combined with antipsychotics in schizophrenia.

Attempts to determine why some patients respond to electroconvulsive therapy (ECT) are valuable in schizophrenia. Schizophrenia is associated with aberrant dynamic functional architecture, which might impact the efficacy of ECT. We aimed to explore the relationship between pre-treatment temporal variability and ECT acute efficacy. Forty-eight patients with schizophrenia and 30 healthy controls underwent functional magnetic resonance imaging to examine whether patterns of temporary variability of functional architecture differ between high responders (HR) and low responders (LR) at baseline. Compared with LR, HR exhibited significantly abnormal temporal variability in right inferior front gyrus (IFGtriang.R), left temporal pole (TPOsup.L) and right middle temporal gyrus (MTG.R). In the pooled patient group, ∆PANSS was correlated with the temporal variability of these regions. Patients with schizophrenia with a distinct dynamic functional architecture appear to reveal differential response to ECT. Our findings provide not only an understanding of the neural functional architecture patterns that are found in schizophrenia but also the possibility of using these measures as moderators for ECT selection.

The Off-Target Effect of CRISPR-Cas12a System toward Insertions and Deletions between Target DNA and crRNA Sequences.

The CRISPR-Cas12a system is a new type of genome editing tool with high efficiency and targeting. However, other sequences in the genome may also be cleaved nonspecifically, resulting in unavoidable off-target effects. Therefore, it is necessary to learn more about the mechanism of CRISPR-Cas12a to recognize target sequences to avoid its off-target effects. Here, we show that insertion (DNA bubble) or deletion (RNA bubble) of the target dsDNA sequence compared with the crRNA sequence, the CRISPR-Cas12a system can still recognize and cleave the target dsDNA sequence. We conclude that the tolerance of CRISPR-Cas12a to the bubbles is closely related to the location and size of the bubble and the GC base content of crRNA. In addition, we used the unique property of CRISPR-Cas12a to invent a new method to detect mutations and successfully detect the CD41-42(-CTTT) mutation. The detection limit of this method is 0.001%. Overall, our results strongly indicate that in addition to considering off-target effects caused by base mismatches, a comprehensive off-target analysis of the insertion and deletion of the target dsDNA sequence is required, and specific guidelines for effectively reducing potential off-target cleavage are proposed, to improve the safety manual of CRISPR-Cas12a biological application.

Laparoscopic vs. open procedure for intermediate­ and high­risk endometrial cancer: a minimum 4-year follow-up analysis.

BACKGROUND: The long-term oncologic outcomes after laparoscopic and open procedures for patients with intermediate­ and high­risk endometrial cancer (EC) remain unclear. Accordingly, laparoscopy cannot still be recommended as the standard choice for intermediate­ and high­risk EC. This retrospective study aimed to assess the perioperative and long-term oncologic outcomes of laparoscopy and open surgery in patients with intermediate- and high­risk ECs within a minimum 4-year follow-up. METHODS: We included 201 patients who underwent laparoscopic or open procedures for intermediate­ and high­risk EC between 2010 and 2017. Between-procedure comparisons of perioperative and oncological outcomes were performed using the independent t-test or Pearson's chi-squared test and the Kaplan-Meier method, respectively. RESULTS: Finally, there were 136 intermediate­ and 65 high­risk endometrial tumors in the laparoscopic and open groups, respectively. There were no between-group differences in all baseline characteristics. Compared with the open group, the laparoscopic group had a significantly longer mean operating time (p = 0.005) and a lower mean estimated blood loss (EBL) (p = 0.031). There was a higher possibility of postoperative complication in the open group than in the laparoscopic group (p = 0.048). There were no significant between-group differences in pathological outcomes as well as the recurrence-free survival and overall survival rates (p = 0.626 and p = 0.148, respectively). CONCLUSIONS: Among patients with intermediate­ and high­risk EC, laparoscopic surgery has an advantage over the open surgery in reducing EBL and the rate of postoperative complications without weakening the oncological control. There were no between-procedure differences in the recurrence-free and overall survival rates.

Magnetic Resonance Imaging throughout the Clinical Course of Schizophrenia: Neurobiological Underpinnings and Clinical Implications.

As a non-invasive detection method and an advanced imaging method, magnetic resonance imaging (MRI) has been widely used in the research of schizophrenia. Although a large number of neuroimaging studies have confirmed that MRI can display abnormal brain phenotypes in patients with schizophrenia, no valid uniform standard has been established for its clinical application. On the basis of previous evidence, we argue that MRI is an important tool throughout the whole clinical course of schizophrenia. The purpose of this commentary is to systematically describe the role of MRI in schizophrenia and to provide references for its clinical application.

Perceived uncertainty stress and its predictors among residents in China during the COVID-19 pandemic.

The prevalence of and risk factors for uncertainty stress among residents during the COVID-19 pandemic remain unclear. An online cross-sectional survey was conducted to explore and identify the risk factors for high perceived uncertainty stress among the general public in China during the COVID-19 outbreak. Information about the respondents' socioeconomic characteristics, knowledge of and attitudes towards COVID-19, perceived uncertainty stress, social capital, anxiety, and depressive symptoms was collected and analysed. Among the 1205 respondents, 45.3% (546) reported a high level of uncertainty stress. Multiple linear regression analysis indicated that anxiety (ß=3.871,P<0.001) and depression symptoms (ß=2.458, P<0.001), family residence (in towns or rural areas) (ß=0.947, P<0.001), lack of support for local epidemic control strategies (ß=1.253, P<0.001), worry about the pandemic (ß=1.191, P<0.001), and symptoms of weakness among family members (ß=1.525, P=0.002) were positively associated with perceived uncertainty stress. Cognitive social capital (ß=-0.883, P<0.001) and social networks (ß=-0.726, P<0.001) were negatively, but social participation (ß=0.714, P<0.001) was positively associated with perceived uncertainty stress. Our findings identify factors associated with a higher level of uncertainty stress and should be helpful in the consideration of effective policies and interventions for uncertainty stress during the initial phases of public health emergencies.

[Determination of absolute configuration of a new triterpenic acid in leaves of Ilex hainanensis].

This study aimed to explore the triterpenic acid components in leaves of Ilex hainanensis. Alkaline water extraction, macroporous resin adsorption, and high performance liquid chromatography were used to separate and purify the triterpenic acid components in leaves of I. hainanensis. The physical and chemical property analysis, MS, NMR spectroscopy, and literature comparison were performed to identify the structures, and a new triterpene acid compound was discovered:(3S, 4R, 5R, 8R, 9R, 10R, 14S, 17S, 18S, 19R)-3,19-dihydroxyursa-12,20(30)-diene-24,28-dioic-acid, and named ilexhainanin F. In addition, according to its structural characteristics, the ~(19)F-NMR Mosher method was further employed to study its absolute configuration. By comparison of the ~(19)F-NMR chemical shifts of Mosher esters, it was determined that the absolute configuration of the 3-position chiral center of the compound was the S configuration.

Taiwan's COVID-19 response: Timely case detection and quarantine, January to June 2020.

The coronavirus disease 2019 (COVID-19) pandemic has become severe threats to economic, societal, and healthcare systems. To analyze the epidemiological characteristics of the COVID-19 outbreak in Taiwan and evaluate the key interventions, we conducted a retrospective cohort study during January 17-June 30, 2020. As of June 30, the COVID-19 outbreak, including 447 laboratory-confirmed cases, was eliminated by mixed approaches: border control, enhanced surveillance, case detection with contact tracing, quarantine, and population-based interventions like face mask use. The improvement of median time from disease onset to notification (5 days [range -3 to 27] before March 1 to 1 day [range -8 to 22] after March 1) suggested the timeliness and comprehensiveness of surveillance and contact tracing. Travel restrictions with quarantine, resulting in fewer clusters, were also complementary to minimize disease spread. Under combined interventions, Taiwan successfully contained the COVID-19 spread within the country and minimized its impact on the society.

Genetic analysis and fine mapping of the gall midge resistance gene Gm5 in rice (Oryza sativa L.).

KEY MESSAGE: The rice gall midge resistance gene, Gm5, confers remarkable antibiosis and is located in the same region on chromosome 12 in three different rice varieties. Fine mapping narrowed this region to a 49-kb segment and identified two candidate genes showing remarkable response to GM infestation. The Asian rice gall midge (GM; Orseolia oryzae; Diptera: Cecidomyiidae) invades rice shoots and forms galls, adversely affecting plant growth and yield production. Thus, the development of resistant varieties through the identification, mapping, and application of GM resistance genes is considered the most efficient strategy for managing this insect. Here, a GM resistance survey of F2 populations derived from intercrosses between resistant rice varieties 'ARC5984,' '570011,' and 'ARC5833' indicated that the resistance gene Gm5 was located on the same chromosomal region in the three varieties. For the initial mapping, three independent F2 mapping populations were developed for the three resistant varieties, and the Gm5 gene was consistently mapped to the same chromosomal region near marker 12M22.6. Fine mapping, which was conducted using the BC1F2 and BC2F2 populations derived from the 9311/ARC5984 cross, narrowed the Gm5 gene region to a 49-kb segment flanked by the markers Z57 and Z64. In the final mapped region, we detected 10 candidate genes, of which six were analyzed for their relative expression. Consequently, two of these genes, Os12g36830 and Os12g36880, showed significantly higher expression in GM-resistant plants than in GM-susceptible plants at 24 and 72 h after GM infestation. Finally, the PCR amplification of markers 12M22.5 and 12M22.6 yielded clear single bands, and these markers were effectively applied for the marker-assisted selection (MAS) of the Gm5 gene. With the developed MAS markers, the fine mapping of this resistance gene will facilitate its map-based cloning and incorporation into insect-resistant rice varieties through breeding.

Mapping and characterization of a quantitative trait locus resistance to the brown planthopper in the rice variety IR64.

BACKGROUND: Rice planthoppers (main brown planthopper, Nilaparvata lugens Stål; BPH) was one of substantial threats to Asia rice production as its serious destruction and difficulties in control under field conditions. Notably, host-plant resistance was proved to be one of the effective ways to manage the pest. And stronger virulence will probably emergence when continuous use of insecticides. Therefore, more resistance genes with different resistance mechanisms were needed to be detected and then applied in the rice breeding practice. RESULTS: Resistance genes in the rice variety IR64 were evaluated considering the seedling bulk test and seedling survival rate. As a result, a locus with a large LOD score of 7.23 was found between markers RM302 and YM35 on chromosome 1. The locus explained 36.9% of phenotypic variation and was tentatively denominated Bph37. Moreover, Bph1 was detected to be harbored by the markers RM28366 and RM463, and had the largest LOD score of 2.08, explaining 7.7% of phenotypic variance in the same mapping population. Finally, the preliminary-near-isogenic-lines (pre-NILs) carrying Bph37 exhibited significant tolerance to the insects. But no antibiotic or antixenotic effects were observed in the resistant plants when infested with the insects. CONCLUSIONS: We mapped one major BPH resistance gene Bph37 in consideration of seedling survival rate and the resistance lines showed tolerance to BPH. The detected gene should be beneficial for understanding the resistance mechanism of rice to BPH and for insect-resistance rice breeding programs.

[Systematically review of modified Sanzi Yangqin Decoction for treating acute exacerbation of chronic obstructive pulmonary disease].

The randomized controlled trials( RCTs) about modified Sanzi Yangqin Decoction in the treatment of patients with exacerbation of chronic obstructive pulmonary disease( AECOPD) were collected from 7 databases( PubMed,CNKI,etc.) till December25,2018 from their inception. All the studies searched were strictly evaluated and independently screened by two researchers according to the inclusion and exclusion criteria,and the methodological quality of included studies was evaluated. In order to systematically review the efficacy and safety of modified Sanzi Yangqin Decoction for treating AECOPD,the Meta-analysis and trial sequential analysis were conducted by using Stata/SE 14. 0 and TSA 0. 9. 5. 10 Beta,respectively. A total of 22 RCTs involving 2 012 patients were included. The results of Meta-analysis suggested that: as compared with the control group,the clinical symptoms in AECOPD patients were improved( RR = 1. 19,95%CI[1. 15,1. 24],P = 0); the pulmonary functions including forced expiratory volume in one second( FEV_1)( SMD= 0. 96,95%CI[0. 39,1. 52],P= 0. 001),the percentage of forced expiratory volume in one second( FEV_1%)( SMD =0. 80,95%CI[0. 20,1. 41],P = 0. 009),forced vital capacity( FVC)( SMD = 0. 69,95% CI[0. 06,1. 31],P = 0. 032),first seconds breathing volume percentage of forced vital capacity( FEV_1/FVC) were improved( SMD = 0. 81,95%CI[0. 64,0. 97],P = 0);the arterial oxygen partial pressure( PaO_2) was improved( SMD= 0. 87,95%CI[0. 41,1. 32],P= 0); the arterial partial pressure of carbon dioxide( PaCO_2) was decreased( SMD =-0. 91,95%CI[-1. 33,-0. 49],P = 0) in the trial group. In addition,the incidence of adverse reactions in the experimental group was low,and there were no serious adverse events. The trial sequential analysis( TSA) showed that the studies included in the improvement of clinical efficacy had passed the conventional and TSA threshold at the same time,further confirming the efficacy of trial group. This research showed that,conventional Western medicine treatment,combined with modified Sanzi Yangqin Decoction in treating acute exacerbation patients with chronic obstructive pulmonary disease could improve the clinical efficiency and pulmonary functions,improve the PaO_2,decrease the PaCO_2,with a high safety. However,the quality of existing research is low,requiring more high quality clinical trials for further validation.

Ultrahigh Enzyme Activity Assembled in Layered Double Hydroxides via Mg(2+)-Allosteric Effector.

It is well-known that some metal ions could be allosteric effectors of allosteric enzymes to activate/inhibit the catalytic activities of enzymes. In nanobiocatalytic systems constructed based on the positive metal ion-induced allosteric effect, the incorporated enzymes will be activated and thus exhibit excellent catalytic performance. Herein, we present an environmentally friendly strategy to construct a novel allosteric effect-based ß-galactosidase/Mg-Al layered double hydroxide (ß-gal/Mg-Al-LDH) nanobiocatalytic system via the delamination-reconstruction method. The intercalated ß-gal in the LDH galleries changes its conformation significantly due to the Mg(2+)-induced allosteric interactions and other weak interactions, which causes the activation of enzymatic activity. The ß-gal/Mg-Al-LDH nanobiocatalytic system shows much higher catalytic activity and affinity toward its substrate and about 30 times higher catalytic reaction velocity than the free ß-gal, which suggests that Mg(2+)-induced allosteric effect plays a vital role in the improvement of enzymatic performance.

N-heterocyclic carbene-palladium(II)-1-methylimidazole complex catalyzed α-arylation reactions of tetralones with aryl chlorides and further transformation of the products.

NHC-Pd(II)-Im complex 1 has proven to be an efficient catalyst in the reaction between tetralones 2 and aryl chlorides 3, giving the α-arylated tetralones 4 in good to high yields. In addition, if the above reaction mixture was exposed to air at room temperature for another 3 h, the normal α-arylated products 4 can be fully oxidized to 2-aryl-2'-hydroxytetralones 6 in good yields in a one-pot procedure. Furthermore, if the reaction mixture containing the oxidized products 6 was treated with TsOH/toluene solution under reflux for 19 h, the final aromatized products, 2-aryl-naphthalen-1-ols 5 can be achieved in acceptable to moderate yields. All reactions can tolerate various substituents on the tetralones 2 and aryl chlorides 3, thus giving an efficient method for the α-arylation of tetralones and further transformation of the products, and also enriching the applications of NHC-Pd(II) complexes in organic synthesis.

Susceptibility of Aedes albopictus and Aedes aegypti to three imported Chikungunya virus strains, including the E1/226V variant in Taiwan.

BACKGROUND/PURPOSE: An E1/226V variant Chikungunya virus (CHIKV) efficiently transmitted by Aedes albopictus to humans poses a significant threat to public health for those areas with the presence of Aedes albopictus, including Taiwan. METHODS: We infected three imported CHIKV isolates including the E1/226V variant with Ae. albopictus and Aedes aegypti in the laboratory to understand the disease risk. Viral RNA was measured by real time reverse transcription polymerase chain reaction. RESULTS: The viral susceptibility varied by virus strain and mosquito species and strain. The Asian virus strain started to replicate at 5-6 days post infection (dpi) with the maximum virus yield, ranging from 10(3.63) to 10(3.87) at 5-10 dpi in both species. The variant CHIKV Central/East/South African (CESA) virus genotype replicated earlier at 1 dpi with the maximum virus yield ranging from 10(5.63) to 10(6.52) at 3-6 dpi in Ae. albopictus females while the nonvariant virus strain replicated at 1-2 dpi with the maximum virus yield ranging from 10(5.51) to 10(6.27) at 6-12 dpi. In Ae. aegypti, these viruses replicated at 1-2 dpi, with maximum yields at 4-5 dpi (range from 10(5.38) to 10(5.62)). CONCLUSION: We concluded that the risk of CHIKV in Taiwan is high in all distribution areas of Ae. aegypti and Ae. albopictus for the CESA genotype and that the E1/226V variant virus strain presents an even higher risk.