In Vitro Effects of Ginseng and the Seed of Zizyphus jujuba var. spinosa on Gut Microbiota of Rats with Spleen Deficiency

Ginseng and the seed of Zizyphus jujuba var. spinosa, which are traditional Chinese medicinal materials, were often used in ancient Chinese recipes as a pair of medicines. They can replenish the primordial qi and tonify the spleen. This study investigated the effects of ginseng and the seed of Zizyphus jujuba var. spinosa (GS) extract on gut microbiota diversity in rats with spleen deficiency syndrome (SDS). A total of 52 compounds (including 16 flavonoids, 35 saponins, and 1 alkaloid) were identified and analyzed from the GS extract by UPLC‐Q‐Orbitrap‐MS/MS. The GS extract significantly increased the relative abundance of Firmicutes and Bacteroidetes in rats with SDS but decreased that of Proteobacteria and Actinobacteria. At the genus level, the GS extract significantly increased the relative abundance of Lactobacillus and Bifidobacterium in rats with SDS but decreased that of Streptococcus, Escherichia‐Shigella, Veillonella, and Enterococcus. In addition, the GS extract influenced glucose and amino acid metabolism. In summary, the results showed that the GS extract changed the structure and diversity of gut microbiota in rats with SDS and balanced the metabolic process.     

Membrane‐Free Zn/MnO2 Flow Battery for Large‐Scale Energy Storage

The traditional Zn/MnO₂ battery has attracted great interest due to its low cost, high safety, high output voltage, and environmental friendliness. However, it remains a big challenge to achieve long‐term stability, mainly owing to the poor reversibility of the cathode reaction. Different from previous studies where the cathode redox reaction of MnO₂/MnOOH is in solid state with limited reversibility, here a new aqueous rechargeable Zn/MnO₂ flow battery is constructed with dissolution–precipitation reactions in both cathodes (Mn²⁺/MnO₂) and anodes (Zn²⁺/Zn), which allow mixing of anolyte and catholyte into only one electrolyte and remove the requirement for an ion selective membrane for cost reduction. Impressively, this new battery exhibits a high discharge voltage of ≈1.78 V, good rate capability (10C discharge), and excellent cycling stability (1000 cycles without decay) at the areal capacity ranging from 0.5 to 2 mAh cm^‐2. More importantly, this battery can be readily enlarged to a bench scale flow cell of 1.2 Ah with good capacity retention of 89.7% at the 500th cycle, displaying great potential for large‐scale energy storage.     

Dopamine Semiquinone Radical Doped PEDOT:PSS: Enhanced Conductivity,Work Function and Performance in Organic Solar Cells

Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been is applied as hole transport material in organic electronic devices for more than 20 years. However, the redundant sulfonic acid group of PEDOT:PSS has often been overlooked. Herein, PEDOT:PSS‐DA is prepared via a facile doping of PEDOT:PSS with dopamine hydrochloride (DA·HCl) which reacts with the redundant sulfonic acid of PSS. The PEDOT:PSS‐DA film exhibits enhanced work function and conductivity compared to those of PEDOT:PSS. PEDOT:PSS‐DA‐based devices show a power conversion efficiency of 16.55% which is the highest in organic solar cells (OSCs) with (poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)‐4‐fluorothiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithio‐phene))‐co‐(1,3‐di(5‐thiophene‐2‐yl)‐5,7‐bis(2‐ethylhexyl)‐benzo[1,2‐c:4,5‐c′]dithiophene‐4,8‐dione))] (PM6):(2,2′‐((2Z,2′Z)‐((12,13‐bis(2‐ethylhexyl)‐3,9‐diundecyl‐12,13‐dihydro‐[1,2,5]thiadiazolo[3,4‐e]thieno[2′′,3′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2‐g]thieno[2′,3′:4,5]thieno[3,2‐b]indole‐2,10‐diyl)bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile) (Y6) as the active layer. Furthermore, PEDOT:PSS‐DA also exhibits enhanced performance in three other donor/acceptor systems, exhibiting high compatibility in OSCs. This work demonstrates that doping PEDOT:PSS with various amino derivatives is a potentially efficient strategy to enhance the performance of PEDOT:PSS in organic electronic devices.     

Superior Oxygen Reduction Reaction on Phosphorus‐Doped Carbon Dot/Graphene Aerogel for All‐Solid‐State Flexible Al–Air Batteries

Carbon dots have been recognized as one of the most promising candidates for the oxygen reduction reaction (ORR) in alkaline media. However, the desired ORR performance in metal–air batteries is often limited by the moderate electrocatalytic activity and the lack of a method to realize good dispersion. To address these issues, herein a biomass‐deriving method is reported to achieve the in situ phosphorus doping (P‐doping) of carbon dots and their simultaneous decoration onto graphene matrix. The resultant product, namely P‐doped carbon dot/graphene (P‐CD/G) nanocomposites, can reach an ultrahigh P‐doping level for carbon nanomaterials. The P‐CD/G nanocomposites are found to exhibit excellent ORR activity, which is highly comparable to the commercial Pt/C catalysts. When used as the cathode materials for a primary liquid Al–air battery, the device shows an impressive power density of 157.3 mW cm^?2 (comparing to 151.5 mW cm^?2 of a similar Pt/C battery). Finally, an all‐solid‐state flexible Al–air battery is designed and fabricated based on our new nanocomposites. The device exhibits a stable discharge voltage of ≈1.2 V upon different bending states. This study introduces a unique biomass‐derived material system to replace the noble metal catalysts for future portable and wearable electronic devices.     

Building Electron/Proton Nanohighways for Full Utilization of Water Splitting Catalysts

Low electron/proton conductivities of electrochemical catalysts, especially earth‐abundant nonprecious metal catalysts, severely limit their ability to satisfy the triple‐phase boundary (TPB) theory, resulting in extremely low catalyst utilization and insufficient efficiency in energy devices. Here, an innovative electrode design strategy is proposed to build electron/proton transport nanohighways to ensure that the whole electrode meets the TPB, therefore significantly promoting enhance oxygen evolution reactions and catalyst utilizations. It is discovered that easily accessible/tunable mesoporous Au nanolayers (AuNLs) not only increase the electrode conductivity by more than 4000 times but also enable the proton transport through straight mesopores within the Debye length. The catalyst layer design with AuNLs and ultralow catalyst loading (≈0.1 mg cm^?2) augments reaction sites from 1D to 2D, resulting in an 18‐fold improvement in mass activities. Furthermore, using microscale visualization and unique coplanar‐electrode electrolyzers, the relationship between the conductivity and the reaction site is revealed, allowing for the discovery of the conductivity‐determining and Debye‐length‐determining regions for water splitting. These findings and strategies provide a novel electrode design (catalyst layer + functional sublayer + ion exchange membrane) with a sufficient electron/proton transport path for high‐efficiency electrochemical energy conversion devices.     

Codoped Holey Graphene Aerogel by Selective Etching for High‐Performance Sodium‐Ion Storage

The pursuit of more efficient carbon‐based anodes for sodium‐ion batteries (SIBs) prepared from facile and economical methods is a very important endeavor. Based on the crystallinity difference within carbon materials, herein, a low‐temperature selective burning method is developed for preparing oxygen and nitrogen codoped holey graphene aerogel as additive‐free anode for SIBs. By selective burning of a mixture of graphene and low‐crystallinity carbon at 450 °C in air, an elastic porous graphene monolith with abundant holes on graphene sheets and optimized crystallinity is obtained. These structural characteristics lead to an additive‐free electrode with fast charge (ions and electrons) transfer and more abundant Na⁺ storage active sites. Moreover, the heteroatom oxygen/nitrogen doping favors large interlayer distance for rapid Na⁺ insertion/extraction and provides more active sites for high capacitive contribution. The optimized sample exhibits superior sodium‐ion storage capability, i.e., high specific capacity (446 mAh g^?1 at 0.1 A g^?1), ultrahigh rate capability (189 mAh g^?1 at 10 A g^?1), and long cycle life (81.0% capacity retention after 2000 cycles at 5 A g^?1). This facile and economic strategy might be extended to fabricating other superior carbon‐based energy storage materials.     

Epidemiological,Clinical and Serological Characteristics of Children with Coronavirus Disease 2019 in Wuhan: A Single-centered,Retrospective Study

In December 2019, SARS-CoV-2 was first detected in the samples obtained from three adult patients who suffered from an unknown viral pneumonia in Wuhan (Li et al. 2020). This unknown viral pneumonia is further named as coronavirus disease 2019 (COVID-19) by the World Health Organization. To date, the number of new COVID-19 cases has continued to skyrocket and the impact of SARS-CoV-2 on humans is far greater than any pathogen of this century in both breadth and depth. Previous studies have shown that adults with COVID-19 have symptoms of fever, dry cough, dyspnea, fatigue and lymphocytopenia. Moreover, COVID-19 is more likely to cause death in the elderly, especially those with chronic comorbidities (Huang et al. 2020). In Wuhan, more than 50, 000 COVID-19 cases have been confirmed, including over 780 pediatric patients, and only one child death case (Lu et al. 2020). Although the number of children cases was far fewer than that of adults, COVID-19 might endanger children's health and the information on children remains limited, especially in serological study. In the retrospective study, the investigators analyzed the epidemiological, clinical and serological characteristics of children with COVID-19 in Wuhan in the early stages of the outbreak, which might provide theoretical and practical help in controlling COVID-19 and similar emerging infectious diseases in the future.     

Evidence of compliance with and effectiveness of guidelines for noninvasive prenatal testing in China: a retrospective study of 189,809 cases

In China,the medical guidelines recommend performing noninvasive prenatal testing (NIPT) with caution for pregnant women aged 35 years or older.However,the Mother and Child Health Care Law suggests that all primiparous women whose age is older than 35 years undergo prenatal diagnosis.These two inconsistent suggestions/recommendations have made obstetricians confused about whether to offer NIPT to these older pregnant women.To face this issue and find out the solution we performed a retrospective study of 189,809 NIPT samples collected from 28 provincial-leveled administrative units in China.Of 1,564women with high-risk pregnancies who underwent NIPT,459 (29.3%) did not participate in follow-up.The compound sensitivity and specificity of NIPT for trisomies 21,18 and 13 detection was 99.1%(95%CI,98.0%-99.6%) and 99.9%(95%CI,98.8%-99.9%),respectively.In secundiparous women,NIPT showed high sensitivity and specificity similar to that in primiparous women.The observed risk for trisomies 21 and 18 significantly increased when the maternal age was 39 and older.After the publication of the current NIPT policy,the follow-up rate at our center was 97.9%;however,a large number of women are not in maternal and infant care networks nationwide,and that makes the follow-up rate outside our center relatively low.Our study shows that to balance the prevention of major aneuploidies and the limited resources for prenatal diagnosis,the cut-off age of 35for invasive prenatal diagnosis might be unnecessary.Although the NIPT guidelines are well written,how to practice it effectively,especially in less industrialized areas,is worth discussing.