ObjectiveRecent non-invasive prenatal testing (NIPT) technologies are based on next-generation sequencing (NGS). NGS allows rapid and effective clinical diagnoses to be determined with two common sequencing systems: Illumina and Ion Torrent platforms. The majority of NIPT technology is associated with Illumina platform. We investigated whether fetal trisomy 18 and 21 were sensitively and specifically detectable by semiconductor sequencer: Ion Proton.MethodsFrom March 2012 to October 2013, we enrolled 155 pregnant women with fetuses who were diagnosed as high risk of fetal defects at Xiamen Maternal & Child Health Care Hospital (Xiamen, Fujian, China). Adapter-ligated DNA libraries were analyzed by the Ion Proton™ System (Life Technologies, Grand Island, NY, USA) with an average 0.3× sequencing coverage per nucleotide. Average total raw reads per sample was 6.5 million and mean rate of uniquely mapped reads was 59.0%. The results of this study were derived from BWA mapping. Z-score was used for fetal trisomy 18 and 21 detection.ResultsInteractive dot diagrams showed the minimal z-score values to discriminate negative versus positive cases of fetal trisomy 18 and 21. For fetal trisomy 18, the minimal z-score value of 2.459 showed 100% positive predictive and negative predictive values. The minimal z-score of 2.566 was used to classify negative versus positive cases of fetal trisomy 21.ConclusionThese results provide the evidence that fetal trisomy 18 and 21 detection can be performed with semiconductor sequencer. Our data also suggest that a prospective study should be performed with a larger cohort of clinically diverse obstetrics patients.

The current pneumonia epidemic could evolve into a pandemic on a global scale if not effectively contained. The COVID-19 virus possesses a 61-amino acid open reading frame resembling SARS-CoV virulence factor - ORF6 peptide. The isoleucine content is 15.9% in ORF6 of SARS-CoV versus 16.4% of that in SARS-CoV-2. Given the proton affinity in the carbonyl oxygen in isoleucine, augmented proton traffic can enhance proton-ion antiport and prompt cell swelling. Calorie restriction has been confirmed in animal studies to extend lifespan, and its underlying mechanism is not fully known. As the content of essential amino acids in the open reading frame of SARS-CoV-2 reaches 57.4%, a starch/vitamin diet served for short period of time does not give rise to essential amino acids and halts virion production, which could be adopted as prophylactic approach of many viral infections. Plant-based diet or fasting/boiled rice water can also minimize the intake of essential amino acids or all amino acids respectively. Furthermore, several proteins of SARS-CoV-2 possess high valine plus glycine content which is implicated in heart disease, justifying the aforementioned approaches.

Chlamydia psittaci infection in humans, also known as psittacosis, is usually believed to be an uncommon disease which mainly presents as community-acquired pneumonia (CAP). It is usually sporadic, but outbreaks of infection may occasionally occur. In outbreaks, diagnosis and investigations were usually hampered by the non-specificity of laboratory testing methods to identify C. psittaci. In this study, we use metagenomic next-generation sequencing (mNGS) in the diagnosis of a family outbreak of psittacosis under COVID-19. Three members of an extended family of 6 persons developed psittacosis with pneumonia and hepatic involvement with common symptoms of fever and weakness. Two newly purchased pet parrots which had died successively were probably the primary source of infection. Imagings show lung consolidations and infiltrates, which are difficult to be differentiated from CAP caused by other common pathogens. mNGS identified the infecting agent as C. psittaci rapidly within 48h. The results of this work suggest that there are not characteristic clinical manifestations and imagings of psittacosis pneumonia which can differentiate from CAP caused by other pathogens.The use of mNGS can improve accuracy and reduce the delay in diagnosis of psittacosis especially during the outbreak, which can shorten the course of the disease control. Family outbreak under COVID-19 may be related to the familial aggregation due to the epidemic. To our knowledge, this is the first reported family outbreak of psittacosis in China, and the first reported psittacosis outbreak identified by the method of mNGS in the world.

Several tricyclic phenoxasilin and phenazasiline heterocycles were synthesized from the corresponding 2,2‘-dilithio-diphenyl ether or diphenyl amine precursor and silicon tetrachloride (or trichlorosilane) followed by reduction with lithium aluminum hydride [H2SiAr2:  Ar2 = C12H8O (1); Ar2 = C14H12O (2); Ar2 = C13H11N (3); Ar2 = C15H15N (4); Ar2 = C13H9Br2N (5)]. The reactivity of hydrosilanes 1−5 with (Ph3P)2Pt(η2-C2H4) (6) was investigated. At room temperature, mononuclear complexes, (Ph3P)2Pt(H)(SiAr2H) and (Ph3P)2Pt(SiAr2H)2, were generally observed by NMR spectroscopy but were too reactive or unstable to isolate. Dinuclear and in some cases trinuclear Pt−Si-containing complexes were observed as the major products from the reactions. Symmetrical dinuclear complexes, [(Ph3P)Pt(μ-η2-H-SiAr2)]2 (8 and 22, respectively), were produced from the reaction of 1 or 3 with 6. In contrast, reaction of silane 2 with 6 produced a trinuclear complex, [(Ph3P)Pt(μ-SiAr2)]3 (16), as the major product. However, reaction of 4 or 5 with complex 6 produced an unsymmetrical dinuclear complex, [(Ph3P)2Pt(H)(μ-SiAr2)(μ-η2-H-SiAr2)Pt(PPh3)] (26 and 30, respectively), as the major component. The molecular structures of a symmetrical (22) and unsymmetrical dinuclear (30) complex as well as a trinuclear (16) complex were determined by X-ray crystallography.

The reaction of diphenylgermane (Ph 2 GeH 2 ) with (Ph 3 P) 2 Pt(η 2 -C 2 H 4 ) provided both mononuclear (Ph 3 P) 2 Pt(H)(GePh 2 H) and dinuclear [(Ph 3 P)Pt(µ-η 2 -H-GePh 2 )] 2 complexes. The structure of the dinuclear complex was determined by X-ray crystallography. The dinuclear complex could also be obtained from an unusual exchange reaction involving the unsymmetrical dinuclear complex [(Ph 3 P) 2 (H)Pt(µ-SiR 2 )(µ-η 2 -H-SiR 2 )-Pt(PPh 3 )] (SiR 2 ) SiC 20 H 24 ) with Ph 2 GeH 2 .