Recent progress on rapid diagnosis of COVID-19 by point-of-care testing platforms.

The outbreak of COVID-19 has drawn great attention around the world. SARS-CoV-2 is a highly infectious virus with occult transmission by many mutations and a long incubation period. In particular, the emergence of asymptomatic infections has made the epidemic even more severe. Therefore, early diagnosis and timely management of suspected cases are essential measures to control the spread of the virus. Developing simple, portable, and accurate diagnostic techniques for SARS-CoV-2 is the key to epidemic prevention. The advantages of point-of-care testing technology make it play an increasingly important role in viral detection and screening. This review summarizes the point-of-care testing platforms developed by nucleic acid detection, immunological detection, and nanomaterial-based biosensors detection. Furthermore, this paper provides a prospect for designing future highly accurate, cheap, and convenient SARS-CoV-2 diagnostic technology.

[Influence of processing factors on honey-fried Codonopsis Radix].

The present study investigated the influence of heating and honey addition on the appearance, chemical component content, and pharmacological activity of Codonopsis Radix decoction pieces in the honey-frying process, and explored the processing mechanism of honey-fried Codonopsis Radix. The color, sweetness, and content of macromolecular components(e.g., oligosaccharides and polysaccharides) and small molecular components(e.g., lobetyolin and atractylenolide Ⅲ) of raw Codonopsis Radix, fried Codonopsis Radix, honey-mixed Codonopsis Radix, and honey-fried Codonopsis Radix were determined, and the antioxidant activities in vitro of their water extract, polysaccharide extract, and oligosaccharide extract were compared. The results showed that in terms of color and sweetness, compared with the raw Codonopsis Radix, the fried Codonopsis Radix slightly changed, the honey-mixed Codonopsis Radix changed significantly, and the honey-fried Codonopsis Radix changed with high significance. In terms of the content of lobetyolin, atractylenolide Ⅲ, and polysaccharides, the samples were ranked as raw Codonopsis Radix > fried Codonopsis Radix > honey-mixed Codonopsis Radix > honey-fried Codonopsis Radix, which indicated that heating and honey addition could reduce the content of these three components. In terms of the content of oligosaccharides, the samples were ranked as honey-fried Codonopsis Radix ≈ honey-mixed Codonopsis Radix > fried Codonopsis Radix ≈ raw Codonopsis Radix, indicating that honey addition could increase the content of oligosaccharides. In terms of antioxidant activity in vitro, ABTS radical scavenging ability of water extract, polysaccharides, and oligosaccharides of honey-fried Codonopsis Radix was most potent, while the change of antioxidant activity in vitro of each extract in the other three processed products was different. In short, both heating and honey addition can affect the appearance, chemical component content, and antioxidant activity in vitro of Codonopsis Radix decoction pieces, but the effect of the combination of the two factors is the best. The comprehensive analysis of the effects of heating and honey addition on Codonopsis Radix decoction pieces indicates that honey addition followed by heating at high temperature is the necessary condition for honey-fried Codonopsis Radix to enhance its activity.

Gallic Acid Inhibits Mesaconitine-Activated TRPV1-Channel-Induced Cardiotoxicity.

Aconiti Kusnezoffii Radix (Caowu) is often combined or processed with Chebulae Fructus (Hezi) to achieve attenuation purposes in Mongolian medicine. Mesaconitine (MA), a main bioactive ingredient of Caowu, is also famous for its high cardiotoxicity while exerting good anti-inflammatory and analgesic properties. Gallic acid (GA), one of the leading chemical components in Hezi, possesses cardiac protection. This study aimed to clarify the detoxification effects of GA from Hezi on MA-induced cardiotoxicity and whether the detoxification mechanism is related to the TRPV1 channel. Cell viability was determined by methyl thiazol tetrazolium (MTT), and lactate dehydrogenase (LDH) leakage rate was determined by ELISA. Hoechst 33258, JC-1, DCFH-DA, and Fluo-3 AM staining were conducted to detect apoptosis, mitochondrial membrane potential, reactive oxygen species (ROS), and Ca2+ respectively; TRPV1 channel current was recorded by whole-cell patch-clamp technology to observe the effect of GA and MA alone or in combination on TRPV1 channel. The results showed that GA exhibited pronounced detoxification effects on MA-induced cardiotoxicity. GA significantly inhibited the MA-induced decrease in cell viability; suppressed the MA-induced LDH leakage rate, apoptosis, and the release of ROS and Ca2+; and alleviated the reduction of mitochondrial membrane potential. We found that MA-induced cardiotoxicity was significantly attenuated in H9c2 cells pretreated with the TRPV1 antagonist BCTC. In the whole-cell patch-clamp experiment, the TRPV1 channel current increase was caused by the GA and MA treatment, whereas it was reduced by the cotreatment of GA and MA. Our data demonstrate that GA in Hezi can reduce MA-induced cardiotoxicity by inhibiting intracellular Ca2+ influx, restoring mitochondrial membrane potential, and reducing apoptosis. The detoxification mechanism may be related to the desensitization of the TRPV1 channel by the combined application of MA and GA.

Advances in the DNA Nanotechnology for the Cancer Biomarkers Analysis: Attributes and Applications.

The most commonly used clinical methods are enzyme-linked immunosorbent assay (ELISA) and quantitative PCR (qPCR) in which ELISA was applied for the detection of protein biomarkers and qPCR was especially applied for nucleic acid biomarker analysis. Although these constructed methods have been applied in wide range, they also showed some inherent shortcomings such as low sensitivity, large sample volume and complex operations. At present, many methods have been successfully constructed on the basis of DNA nanotechnology with the merits of high accuracy, rapid and simple operation for cancer biomarkers assay. In this review, we summarized the bioassay strategies based on DNA nanotechnology from the perspective of the analytical attributes for the first time and discussed and the feasibility of the reported strategies for clinical application in the future.

Changes of Mineralogical Properties and Biological Activities of Gypsum and Its Calcined Products with Different Phase Structures.

Raw gypsum (RG) and calcined gypsum (CG) are widely used in traditional Chinese medicine (TCM). RG is usually taken orally to resolve heat and diminish inflammation, while CG is only used externally to treat ulcerations and empyrosis. Calcination at different temperatures, three phase CG structures, namely, bassanite, anhydrite III, and anhydrite II, may be generated. We herein investigated the relationship between the phase structure and the efficacy of CG and the optimum phase structure for CG. RG has a compact structure, small pore size, weak anti-inflammatory effect, but no antibacterial effect, and has almost no effect on the repair of scalds. CG150 (bassanite) has a loose texture, large pore size and specific surface area, and certain antibacterial and anti-inflammatory effects, but it has a poor repair effect on scalds. CG750 (anhydrite II) has a compact structure, small pore size and specific surface area, and low antibacterial and anti-inflammatory effects, but it has a certain repair effect on scalds. Only CG350 (anhydrite III) has good performance in texture, pore size, specific surface area, antibacterial, anti-inflammatory, and scald repair. Our research has proved that the mineral properties and biological activities of CG are different due to different phase structures. CG350, namely, anhydrite III, is considered by our research to be the optimal phase structure as CG.

The effect of strain on water dissociation on reduced rutile TiO2(110) surface.

The effect of external uniaxial strain on water dissociation on a reduced rutile TiO2(110) surface has been theoretically studied using first-principles calculations. We find that when the tensile strain along [11̄0] is applied, the energy barrier of water dissociation substantially decreases with the increase of strain. In particular, water almost automatically dissociates when the strain is larger than 3%. Besides, the water dissociation mechanism changes from indirect to direct dissociation when the compressive strain is larger than 1.3% along [11̄0] or 3% along [001]. The results strongly suggest that it is feasible to engineer the water dissociation on the reduced rutile TiO2(110) surface using external strain.

[Expression of Versican and Its Related Molecules in Patient with Multiple Myeloma and Its Clinical Significance].

OBJECTIVE: To investigate the expression and clinical significant of VCAN and its related molecules in patients with MM. METHODS: Ficoll density gradient centrifugation method was used to speared the bone marrow mononuclear cell in 25 cases of MM before and after treatment, the relative mRNA expression of VCAN and their related molecules (FAK, FN, MK, and HAS) in bone marrow was detected by real-time quantitative PCR, and their protein expression was determined by Western bolt. RESULTS: The expression of VCAN, FK and FN in the effective group after treatment was significantly lower than that before treatment (P＜0.05), however, the expression of MK and HAS showed no statistically significantly different before and after treatment (P＜0.05). The expression of VCAN of patients in non remission group was significantly higher than that in control group (P＜0.05). The expression of FAK and FN of patients in no remission group was significant increased as compared with the patients in newly diagnosed group (P＜0.05). The relative expression of VCAN mRNA in the patients at 3rd stage was significantly higher than those at the 1st stage (P＜0.05) and control group but showed no significant difference to the patients at 2nd stage (P＜0.05). The expression of VCAN and its related proteins (FAK, MK, FN) showed positively correlation in bone marrow mononuclear cells of MM patients (P＜0.05). The correlation between VCAN and HAS was not statistically significant (r=0.259，P＞0.05). Survival analysis showed that the relative expression of VCAN mRNA was associated with OS (P=0.049) and PFS (P=0.041) in MM patients. CONCLUSION: VCAN and its related molecules are highly expressed in MM patients; VCAN may act as potential biomarker in the development of multiple myeloma.

[Clinical Significance of Platelet Closure Time in Patients with Multiple Myeloma].

OBJECTIVE: To explore the clinical significance of platelet closure time (PCT) in patients with multiple myeloma (MM). METHODS: Peripheral blood samples of 50 newly diagnosed MM patients treated in our hospital from July 2018 to November 2019 and 34 healthy persons underuent physical at the same time were collected. PCT induced by collagen/epinephrine (CEPI) and collagen/adenosinediphosphate (CADP) in peripheral blood were detected by PFA-200，and the clinical data included age, sex, leukocyte count, hemoglobin level, platelet count and level of serum creatinine, cystatin c, blood calcium, ß2-microglobulin (ß2-MG), bone marrow plasma cells, light chain protein, as well as the MM types, ISS stage of patients were collected. RESULTS: The level of PCT in MM patients was significantly higher than that in healthy persons; the level of PCT were significantly increased with the increasing of ISS stage in newly diagnosed MM patients; After chemotherapy with bortezomib/dexamethasone (BD), the level of PCT in 15 patients who were responded to the treatment was significantly lower than those before treatment. CONCLUSION: The platelet closure time is abnormal in MM patients, moreover, relates to the progress of the disease. It has an important clinical significance for the evaluation of diagnostic stage and therapeutic efficacy evaluation of MM patients.

[Expression and Significance of PD-1, TIM-3 and VISTA on T Cell of Acute Myeloid Leukemia Patients].

OBJECTIVE: To study the expression of multiple negative costimulatory molecules on peripheral blood T cells in patients with acute myeloid leukemia (AML) and its affection on prognosis. METHODS: The peripheral blood samples from patients with newly diagnosed AML, complete remission (CR), and no-remission (NR) were collected, the expression levels PD-1、VISTA and TIM-3 in CD4+ and CD8+ T cells were detected by flow cytometry , and the clinical data of patients were analyzed. RESULTS: The expression levels of PD-1、VISTA and TIM-3 of CD4+ and CD8+ T cells in the newly diagnosed AML patients were significantly higher than those in control group (P＜0.05). The expression levels of PD-1、TIM-3 and VISTA of CD4+ and CD8+ T cells in the CR group were significantly lower than those in newly diagnosed and the NR group (P＜0.05). The TIM-3 expression level positively correlated with VISTA expression level of CD4+ and CD8+ T cells in newly diagnosed AML patients (r=0.85 and 0.73). The VISTA and PD-1 expression level of CD4+ T cells in newly diagnosed AML, NR after first induction chemotherapy and high risk patients significantly increased (P＜0.05), the TIM-3 expression level of CD8+ T cells in high risk group significantly increased (P＜0.05), and the VISTA expression level of CD8+ T cells in CBFß-MYH11 mutation-positive group significantly decreased (P＜0.05). CONCLUSION: The expression of PD-1、TIM-3 and VISTA in AML peripheral blood T cells may be involved in the immune escape of AML and can be the targets of treatment for acute myeloid leukemia patients.

[Functional movement disorders in children and adolescents].

Functional movement disorders (FMDs), also known as psychogenic movement disorders (PMDs), should be considered a biological-psychological-social disease like other functional neurological diseases. It is not merely a psychological or mental disease. The etiology of FMDs includes neurobiological changes, such as abnormal patterns of cerebral activation and abnormal connectivity between the limbic system and the motor networks. Inheritance and epigenetic machinery, such as DNA methylation and changes in grey and white matter morphology, may influence the development of FMDs. FMDs are not rare in the outpatient service of pediatrics and are one of the most challenging movement disorders due to complex and diversified clinical manifestations. Due to a lack of clinical knowledge and unified diagnostic criteria, it is difficult for pediatricians to make a correct diagnosis of FMDs, which may be easily confused with other diseases. Pediatricians should pay more attention to children with FMDs and establish a multidisciplinary team with psychiatrists, specialists in developmental behavior, and physiotherapists, so as to provide active management and treatment for such children.

[Chemical variation in Aconti Kusnezoffii Radix before and after processing based on UPLC-Orbitrap-MS].

Some Chinese herbal medicine needs to be processed before it can be used as medicine, especially toxic Chinese medicine. Highly toxic Aconti Kusnezoffii Radix(Caowu in Chinese) is widely used in traditional Chinese medicine and Mongolian medicine. In traditional Chinese medicine, Caowu is usually processed by boiling with water(CW) until no white part inside and being tasted without tongue-numbing. In Mongolian medicine, it is usually soaked in Chebulae Fructus(Hezi in Chinese) decoction for several days(CH). Both methods could reduce toxicity according to reports. The biggest difference between CW and CH is that CW needs to be heated for 4-6 h, while CH needs Hezi as processing adjuvants. To explore the toxicity reduction mechanism of CW and CH, we studied the contents of various compounds in Caowu processed by two methods by UPLC-Orbitrap-MS. The results indicated that CW had 14 new ingredients, such as 14-O-anisoylneoline and dehydro-mesaconitine, while N-demethyl-mesaconitine and aconitine disappeared. At the same time, it could significantly decrease the content of diester diterpenoid alkaloids and increase the contents of monoester diterpenoid alkaloids and amine-diterpenoid alkaloids. CH had 9 new ingredients from Hezi, like gallic acid, chebulic acid and shikimic acid. Neither the kinds nor the contents of compositions from Caowu in CH changed little. This suggested that the processing mechanism of CW reduced highly toxic components(diester diterpenoid alkaloids) and increased the content of lowly toxic components(monoester diterpenoid alkaloids and amine-diterpenoid alkaloids). Attenuated principle of CH may be related to the components of Hezi. In this experiment, the conclusion shows that the chemical constituents of CW and CH are essentially different, and the two methods have different toxicity reduction principles.

Selective brain hypothermia-induced neuroprotection against focal cerebral ischemia/reperfusion injury is associated with Fis1 inhibition.

Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke, and avoids the complications of general hypothermia. However, the mechanisms by which selective brain hypothermia affects mitochondrial fission remain unknown. In this study, we investigated the effect of selective brain hypothermia on the expression of fission 1 (Fis1) protein, a key factor in the mitochondrial fission system, during focal cerebral ischemia/reperfusion injury. Sprague-Dawley rats were divided into four groups. In the sham group, the carotid arteries were exposed only. In the other three groups, middle cerebral artery occlusion was performed using the intraluminal filament technique. After 2 hours of occlusion, the filament was slowly removed to allow blood reperfusion in the ischemia/reperfusion group. Saline, at 4°C and 37°C, were perfused through the carotid artery in the hypothermia and normothermia groups, respectively, followed by restoration of blood flow. Neurological function was assessed with the Zea Longa 5-point scoring method. Cerebral infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride staining, and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. Fis1 and cytosolic cytochrome c levels were assessed by western blot assay. Fis1 mRNA expression was assessed by quantitative reverse transcription-polymerase chain reaction. Mitochondrial ultrastructure was evaluated by transmission electron microscopy. Compared with the sham group, apoptosis, Fis1 protein and mRNA expression and cytosolic cytochrome c levels in the cortical ischemic penumbra and cerebral infarct volume were increased after reperfusion in the other three groups. These changes caused by cerebral ischemia/reperfusion were inhibited in the hypothermia group compared with the normothermia group. These findings show that selective brain hypothermia inhibits Fis1 expression and reduces apoptosis, thereby ameliorating focal cerebral ischemia/reperfusion injury in rats. Experiments were authorized by the Ethics Committee of Qingdao Municipal Hospital of China (approval No. 2019008).

[Persistent hypertension for two months in a preterm infant].

A boy aged 2 months (born at 36 weeks of gestation) was admitted due to cough and dyspnea. After admission, he was found to have persistent hypertension, proteinuria, and persistent convulsion, and imaging examination showed extensive calcification of the aorta and major branches and stenosis of local lumens of the abdominal aorta and the right renal artery with increased blood flow velocity. The boy was admitted during the neonatal period due to wet lung and pulmonary arterial hypertension and was found to have hypertension and proteinuria. High-throughput whole-exome sequencing was performed and found two compound heterozygous mutations in the ENPP1 gene from his parents, c.130C>T (p.Q44X) and c.1112A>T (p.Y371F). c.130C>T was a nonsense mutation, which could cause partial deletion of protein from 44 amino acids, and was defined as a primary pathogenic mutation. c.1112A>T was a missense mutation which had been reported as a pathogenic mutation associated with idiopathic infantile arterial calcification (IIAC). Therefore, he was diagnosed with IIAC. He was given phosphonate drugs, antihypertensive drugs, anticonvulsion treatment, and respiratory support. Blood pressure was maintained at the upper limit of normal value. There was no deterioration of arterial calcification. It is concluded that IIAC should be considered for infants with persistent hypertension and extensive vascular calcification, and imaging and genetic examinations should be performed as early as possible to make a confirmed diagnosis.

First-principle study of structural, electronic and magnetic properties of (FeC)n (n = 1-8) and (FeC)8TM (TM = V, Cr, Mn and Co) clusters.

The structural, electronic and magnetic properties of the (FeC)n (n = 1-8) clusters are studied using the unbiased CALYPSO structure search method and density functional theory. A combination of the PBE functional and 6-311 + G* basis set is used for determining global minima on potential energy surfaces of (FeC)n clusters. Relatively stabilities are analyzed via computing their binding energies, second order difference and HOMO-LUMO gaps. In addition, the origin of magnetic properties, spin density and density of states are discussed in detail, respectively. At last, based on the same computational method, the structures, magnetic properties and density of states are systemically investigated for the 3d (V, Cr, Mn and Co) atom doped (FeC)8 cluster.

Insights into the structures and electronic properties of Cun+1µ and CunS µ (n = 1-12; µ = 0, ±1) clusters.

ABSTARCT: The stability and reactivity of clusters are closely related to their valence electronic configuration. Doping is a most efficient method to modify the electronic configuration and properties of a cluster. Considering that Cu and S posses one and six valence electrons, respectively, the S doped Cu clusters with even number of valence electrons are expected to be more stable than those with odd number of electrons. By using the swarm intelligence based CALYPSO method on crystal structural prediction, we have explored the structures of neutral and charged Cun+1 and CunS (n = 1-12) clusters. The electronic properties of the lowest energy structures have been investigated systemically by first-principles calculations with density functional theory. The results showed that the clusters with a valence count of 2, 8 and 12 appear to be magic numbers with enhanced stability. In addition, several geometry-related-properties have been discussed and compared with those results available in the literature.

Theoretical study on Au(I)-catalyzed [2 + 2 + 2] cycloadditions of ynamides with two discrete nitriles.

The Au-catalyzed [2 + 2 + 2] cycloadditions of ynamides with two discrete nitriles were theoretically studied with the aid of DFT calculations. The reaction under consideration is found to start from binding of the catalyst with the ynamide rather than with the nitrile. The Au(i)-ynamide species can effectively induce dimerization of two nitrile molecules while the catalyst only cannot. The Au(i)-ynamide species () is revealed to be more reactive than the Au(i)-nitrile species. Also, the regioselectivity and the influence of EWG vs. EDG involved in the reaction were also rationalized.

[Rapid Start-up of Simultaneous Nitrification and Denitrification Coupled Phosphorus Removal Process and Its Performing Characteristics].

In this study, simultaneous nitrification and denitrification (SND) coupled Phosphorus removal process through gradually decreasing DO concentration was investigated by treating wastewater with a low COD/TN ratio (C/N = 3 : 1-4: 1) in a sequencing batch reactor (SBR) inoculated with aerobic granular sludge (AGS). Successful SND coupled Phosphorus phenomenon occurred after 20d at the DO concentration of 0.50-1.0 mg x L(-1). In the following 40 days, the average removal rates of COD, NH4(+) -N, TN and TP were 84.84% , 93.51%, 77.06% and 85.69%, and the NO3(-) -N and NO2(-) -N average accumulations in the effluent were only 4.01 mg x L(-1) and 3.17 mg x L(-1), respectively. The AGS had complete forms and good settling performances, and the sludge volume index (SVI) was about 55.22 mL x g(-1) at the end of starting-up stage. The results of different nitrogen sources showed that the removal rate of TN was in the order of NH4(+) -N > NO2(-) -N > NO3(-) -N, and the removal rate of TP was in the order of NO3(-) -N > NO2(-) -N > NH4(+) -N. The nitrogen and phosphorus removal of wastewater were mainly realized by simultaneous nitrification and denitrification and denitrifying phosphorus removal, respectively.

[Clinical features of respiratory diseases in late preterm neonates].

OBJECTIVE: To evaluate the clinical features of respiratory diseases of late preterm neonates. METHODS: Six hundred and thirty late preterm infant(gestational age: 34~36+6weeks),4401 cases of term infants and 328 early preterm infants who were born at the obstetrical department of Peking University 3rd Hospital from January 2009 to December 2010 were enrolled. Among them 84 late preterm infants, 135 term infants and 182 early preterm infants developed respiratory diseases. The incidence of respiratory diseases,clinical features and the severity of the diseases were compared among the three groups. RESULTS: The incidence and mortality rates of respiratory diseases and the percentage of severe cases were significantly higher in the late preterm group than in the term group, but lower than in the early preterm group (P<0.01). The symptoms of respiratory disease occurred earlier in the late preterm group than in the term group, but later than in the early preterm group (P<0.01). The late preterm group had a significantly higher incidence of tachypnea and lower incidence of retraction sign when compared with the term and early preterm groups (P<0.05). The percentages requiring oxygen therapy and mechanical ventilation in the late preterm group were both significantly higher than in the term group, but lower than in the early preterm group (P<0.05). The multiple linear regression analysis showed 11 factors associated with the severity of respiratory diseases: decreased arterial partial pressure of oxygen, hematokrit, pH value and respiratory rate, arterial oxyhemoglobin saturation, systolic arterial pressure, 5 minute Apgar score and gestational age, and increased blood urea nitrogen, heart rate and respiratory rate. CONCLUSIONS: Late preterm infants are more likely to develop respiratory diseases than term infants, and to develop a more severe condition and need a more intensive respiratory support treatment. Tachypnea is a common presentation of dyspnea in late preterm infants and occurs earlier than in term infants but later than in early preterm infants. It may usually indicate a serious condition when dyspnea, abnormal heart rate and blood pressure, and multisystem damages occur in late preterm infants.