Objective:We aim to systematically review the clinical characteristics of Coronavirus disease 2019 .Methods: Seven datebases were searched to collect studies about the clinical characteristics of COVID-19 from 1 January 2020 to 28 February 2020. Then, meta-analysis was performed by using Stata12.0 software. Results:A total of 38 studies involving 3 062 COVID-19 patients were included.Meta-analysis showed that a higher proportion of infected patients were male (56.9%).The incidence rate of respiratory failure or ARDS was 19.5% and the fatality rate was 5.5%. Fever (80.4%), fatigue (46%), cough (63.1%) and expectoration (41.8%) were the most common clinical manifestations. Other common symptoms included muscle soreness (33%), anorexia (38.8%), chest tightness (35.7%), shortness of breath (35%), dyspnea (33.9%). Minor symptoms included nausea and vomiting (10.2%), diarrhea (12.9%), headache (15.4%), pharyngalgia(13.1%), shivering (10.9%) and abdominal pain (4.4%). Patients with asymptomatic was 11.9%. Normal leukocytes counts (69.7%), lymphopenia (56.5%), elevated C-reactive protein levels (73.6%), elevated ESR (65.6%) and oxygenation index decreased (63.6%) were observed in most patients. About 37.2% of patients with elevated D-dimer, 25.9% of patients with leukopenia, along with abnormal levels of liver function (29%) and renal function (25.5%). Other findings included leukocytosis (12.6%) and elevated procalcitonin (17.5%). Only 25.8% of patients had lesions involving single lung and 75.7% of patients had lesions involving bilateral lungs. Conclusions:The most commonly experienced symptoms of COVID-19 patients were fever, fatigue, cough and expectoration. A relatively small percentage of patients were asymptomatic. Most patients showed normal leucocytes counts, lymphopenia, elevated levels of C-reactive protein and ESR. Bilateral lungs involvement was common.

Cytoplasmic male sterility (CMS) has been extensively used for hybrid seed production in many major crops. Honglian CMS (HL-CMS) is one of the three major types of CMS in rice and has contributed greatly to food security worldwide. The HL-CMS trait is associated with an aberrant chimeric mitochondrial transcript, atp6-orfH79, which causes pollen sterility and can be rescued by two nonallelic restorer-offertility (Rf) genes, Rf5 or Rf6. Here, we report the identification of Rf6, which encodes a novel pentatricopeptide repeat (PPR) family protein with a characteristic duplication of PPR motifs 3-5. RF6 is targeted to mitochondria, where it physically associates with hexokinase 6 (OsHXK6) and promotes the processing of the aberrant CMSassociated transcript atp6-orfH79 at nucleotide 1238, which ensures normal pollen development and restores fertility. The duplicated motif 3 of RF6 is essential for RF6-OsHXK6 interactions, processing of the aberrant transcript, and restoration of fertility. Furthermore, reductions in the level of OsHXK6 result in atp6-orfH79 transcript accumulation and male sterility. Together these results reveal a novel mechanism for CMS restoration by which RF6 functions with OsHXK6 to restore HL-CMS fertility. The present study also provides insight into the function of hexokinase 6 in regulating mitochondrial RNA metabolism and may facilitate further exploitation of heterosis in rice.cytoplasmic male sterility | pentatricopeptide repeat | restorer-of-fertility | RF6 | hexokinase 6 P lant cytoplasmic male sterility (CMS) is a trait characterized by a lack of functional pollen grains in plants, although female gametes are still viable (1). CMS has been widely used to produce hybrid seeds to improve plant yield, improve resistance to diseases or stresses, or enhance taste (2). Plant CMS results from genomic incompatibility between mitochondria and nuclei and is typically associated with an aberrant chimeric gene in the mitochondria (3-6). A specific set of nuclear genes called restorer-of-fertility (Rf) genes, which primarily belong to the pentatricopeptide repeat (PPR) family, repress CMS through the promotion of the cleavage, degradation, or editing of CMS-associated aberrant transcripts or the inhibition of the translation of these genes (7-9). PPR proteins regulate RNA metabolism at multiple levels, from RNA editing, stability, processing, and splicing to translation (10, 11). PPR proteins can be classified into PLS and P families based on the structure of PPR motifs (11). PLS family members generally exhibit direct RNA binding (12)(13)(14) or editing activity (15-17), whereas P-family proteins often lack sites for binding to RNA, particularly mitochondrial CMS-related RNA (18,19). Most of the known PPR proteins implicated in restoration of fertility (RF) are P-family members. Thus, RF-related PPR proteins may require additional partners, such as RNA-binding or splicing factors to process CMSrelated transcripts.Rice CMS is categorized into three major types: Wild Abortive (WA), originating from...

Particulate matter 2.5 (

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