Alkaline Phosphatase-Mediated Bioetching of CoOOH/BiVO4 for Signal-On Organic Photoelectrochemical Transistor Bioanalysis.

Organic photoelectrochemical transistor (OPECT) bioanalytics has recently appeared as a promising route for biological measurements, which has major implications in both next-generation photoelectrochemical (PEC) bioanalysis and futuristic biorelated implementations. Via biological dissociation of materials, bioetching is a useful technique for bio-manufacturing and bioanalysis. The intersection of these two domains is expected to be a possible way to achieve innovative OPECT bioanalytics. Herein, we validate such a possibility, which is exemplified by alkaline phosphatase (ALP)-mediated bioetching of a CoOOH/BiVO4 gate for a signal-on OPECT immunoassay of human immunoglobulin G (HIgG) as the model target. Specifically, target-dependent bioetching of the upper CoOOH layer could result into an enhanced electrolyte contact and light accessibility to BiVO4, leading to the modulated response of the polymeric poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) channel that could be monitored by the channel current. The introduced biosensor achieves sensitive detection of HIgG with high selectivity and sensitivity. This work features bioetching-enabled high-efficacy OPECT bioanalysis and is anticipated to serve as a generic protocol, considering the diverse bioetching routes.

Detection and Analysis of Ebola Virus in Sierra Leone-China Friendship Biosafety Laboratory from March 11 to April 20, 2015.

Ebola virus disease reemerged in Western Africa in 2014. Chinese Center for Disease Control and Prevention dispatched the first Ebola virus (EBOV) detection team to run newly established Sierra Leone-China Friendship Biological Safety Laboratory. The aims of study were to understand epidemiology, clinical manifestations and survival time of EBOV in patient's blood. A total of 913 specimens were tested between March 11 and April 20, 2015. EBOV positivity occurred in 7.37% of the blood and 0.53% in throat swabs. Most commonly reported symptoms of laboratory confirmed patients were intense fatigue, anorexia, and fever. EBOV RNAs persisted in blood for almost 4 weeks and the real-time RT-PCR Ct values showed close correlation with the sampling time after onset.

Superprotonic conductivity of ketoenamine covalent-organic frameworks grafted by imidazole-based units.

The achievement of covalent organic frameworks (COFs) with high stability and exceptional proton conductivity is of tremendous practical importance and challenge. Given this, we hope to prepare the highly stable COFs carrying CN connectors and enhance their proton conductivity via a post-modification approach. Herein, one COF, TpTta, was successfully synthesized by employing 1,3,5-triformylphloroglucinol (Tp) and 4,4',4″-(1,3,5-triazine-2,4,6-triyl)-trianiline (Tta) as starting materials, which has a ß-ketoenamine structure bearing a large amount of -NH groups and intramolecular H-bonds. TpTta was then post-modified by inserting imidazole (Im) and histamine (His) molecules, yielding the corresponding COFs, Im@TpTta and His@TpTta, respectively. As a result, their proton conductivities were surveyed under changeable temperatures (30-100 °C) and relative humidities (68-98 %), revealing a degree of temperature and humidity dependence. Impressively, under identical conditions, the optimum proton conductivities of the two post-modified COFs are 1.14 × 10-2 (Im@TpTta) and 3.45 × 10-3 S/cm (His@TpTta), which are significantly greater than that of the pristine COF, TpTta (2.57 × 10-5 S/cm). Finally, their proton conduction mechanisms were hypothesized based on the computed activation energy values, water vapor adsorption values, and structural properties of these COFs. Additionally, the excellent electrochemical stability of the produced COFs was expressed, as well as the prospective application value.

Determination of the water vapor transmission rate of cellulose-based papers by multiple headspace extraction analysis.

This paper presents a multiple headspace extraction (MHE) analysis technique to determine the water vapor transmission rate of cellulose-based papers. The water vapor passing through the sample in a closed headspace vial is determined by MHE-gas chromatography. The results show that the employed method offers good precision (the relative standard deviation < 3.49 %) and good accuracy. The method is rapid and accurate, and is promising for the determination of the water vapor transmission rate of cellulose-based papers in future studies.

The Viral Load of Epstein-Barr Virus in Blood of Children after Hematopoietic Stem Cell Transplantation.

Objective: To detect the Epstein-Barr virus (EBV) viral load of children after hematopoietic stem cell transplantation (HSCT) using chip digital PCR (cdPCR). Methods: The sensitivity of cdPCR was determined using EBV plasmids and the EBV B95-8 strain. The specificity of EBV cdPCR was evaluated using the EBV B95-8 strain and other herpesviruses (herpes simplex virus 1, herpes simplex virus 2, varicella zoster virus, human cytomegalovirus, human herpesvirus 6, and human herpesvirus 7). From May 2019 to September 2020, 64 serum samples of children following HSCT were collected. EBV infection and the viral load of serum samples were detected by cdPCR. The epidemiological characteristics of EBV infections were analyzed in HSCT patients. Results: The limit of detection of EBV cdPCR was 110 copies/mL, and the limit of detection of EBV quantitative PCR was 327 copies/mL for the pUC57-BALF5 plasmid. The result of EBV cdPCR was up to 121 copies/mL in the EBV B95-8 strain, and both were more sensitive than that of quantitative PCR. Using cdPCR, the incidence of EBV infection was 18.75% in 64 children after HSCT. The minimum EBV viral load was 140 copies/mL, and the maximum viral load was 3,209 copies/mL using cdPCR. The average hospital stay of children with EBV infection (184 ± 91 days) was longer than that of children without EBV infection (125 ± 79 days), P = 0.026. Conclusion: EBV cdPCR had good sensitivity and specificity. The incidence of EBV infection was 18.75% in 64 children after HSCT from May 2019 to September 2020. EBV cdPCR could therefore be a novel method to detect EBV viral load in children after HSCT.

LMP2-DC Vaccine Elicits Specific EBV-LMP2 Response to Effectively Improve Immunotherapy in Patients with Nasopharyngeal Cancer.

OBJECTIVE: To evaluate the safety and effectiveness of a vaccine based on latent membrane protein 2 (LMP2) modified dendritic cells (DCs) that boosts specific responses of cytotoxic T lymphocytes (CTLs) to LMP2 before and after intradermal injection in patients with nasopharyngeal carcinoma (NPC). METHODS: DCs were derived from peripheral blood monocytes of patients with NPC. We prepared LMP2-DCs infected by recombinant adenovirus vector expressing LMP2 (rAd-LMP2). NPC patients were immunized with 2 × 10 5 LMP2-DCs by intradermal injection at week 0 and after the second and fourth weeks. Specific responses to LMP2 were detected by enzyme-linked immunospot (ELISPOT) assay at week 0 and at the fifth and eighth weeks. Local clinicians performed the follow-up and tracking of patients. RESULTS: We demonstrated that DCs derived from monocytes displayed typical DC morphologies; the expression of LMP2 in the LMP2-DCs vaccine was confirmed by immunocytochemical assay. Twenty-nine patients with NPC were enrolled in this clinical trial. The LMP2-DCs vaccine was well tolerated in all of the patients. Boosted responses to LMP2 peptide sub-pools were observed in 18 of the 29 patients with NPC. The follow-up data of 29 immunized patients from April, 2010 to April 2015 indicated a five-year survival rate of 94.4% in responders and 45.5% in non-responders. CONCLUSION: In this pilot study, we demonstrated that the LMP2-DCs vaccine is safe and effective in patients with NPC. Specific CTLs responses to LMP2 play a certain role in controlling and preventing the recurrence and metastasis of NPC, which warrants further clinical testing.

3,3'-Bis(3,4,5-trimethoxy-benzo-yl)-1,1'-(o-phenyl-ene)dithio-urea ethanol solvate.

In the mol-ecule of the title compound, C(28)H(30)N(4)O(8)S(2)·C(2)H(6)O, the benzene ring is oriented at dihedral angles of 38.50 (6) and 5.68 (5)° with respect to the trimethoxy-phenyl rings, while the two trimethoxy-phenyl rings are oriented at a dihedral angle of 44.18 (5)°. Intra-molecular N-H⋯O and N-H⋯S hydrogen bonds result in the formation of non-planar six-, seven- and eight-membered rings. The twisting modes of the two side arms are different [C-N-C-O and C-N-C-N torsion angles = 0.1 (3) and 11.8 (3)°, respectively, in one arm, and 4.6 (3) and -11.5 (3)° in the other]. In the crystal structure, inter-molecular N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules.

6-(4-Pyrid-yl)-3-(3,4,5-trimethoxy-phen-yl)-1,2,4-triazolo[3,4-b][1,3,4]thia-diazole.

In the mol-ecule of the title compound, C(17)H(15)N(5)O(3)S, the planar central heterocylic ring system is oriented at dihedral angles of 5.32 (4) and 9.41 (4)°, respectively with respect to trimethoxy-phenyl and pyridine rings. Intra-molecular C-H⋯N, C-H⋯O and C-H⋯S hydrogen bonds result in the formation of a nearly planar six-membered ring, which is oriented at a dihedral angle of 3.07 (5)° with respect to the central heterocylic ring system, and non-planar six- and five-membered rings having twist and envelope conformations, respectively. In the crystal structure, inter-molecular C-H⋯N and C-H⋯O hydrogen bonds link the mol-ecules. There is a C-H⋯π contact between the pyridine ring and a methyl group and a π-π contact between the central heterocylic ring system and the trimethoxy-phenyl ring [centroid-centroid distance = 3.758 (1) Å].

6-(4-Methyl-phen-yl)-3-(3,4,5-trimethoxy-phen-yl)-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole.

In the mol-ecule of the title compound, C(19)H(18)N(4)O(3)S, the central heterocylic ring system is oriented with respect to the trimethoxy-phenyl and 4-methyl-phenyl rings at dihedral angles of 1.1 (5) and 15.1 (5)°, respectively. The dihedral angle between the two benzene rings is 16.1 (4)°. In the crystal structure, mol-ecules are linked by inter-molecular C-H⋯O hydrogen bonds, and an intra-molecular C-H⋯N inter-action also occurs.

3,3'-Di-2-naphthoyl-1,1'-(o-phenyl-ene)dithio-urea.

In the mol-ecule of the title compound, C(30)H(22)N(4)O(2)S(2), the central benzene ring is oriented at dihedral angles of 63.83 (3) and 1.37 (3)° with respect to the naphthalene ring systems, while the two naphthalene ring systems are oriented at a dihedral angle of 62.78 (3)°. Intra-molecular N-H⋯O and N-H⋯N hydrogen bonds result in the formation of one five- and two six-membered rings. The twisting modes of the two side arms are different [C-N-C-O and C-N-C-N torsion angles = 11.1 (4) and 1.5 (3)°, respectively, in one arm, and -2.2 (4) and 0.8 (3)° in the other arm]. In the crystal structure, inter-molecular N-H⋯S hydrogen bonds link the mol-ecules into centrosymmetric dimers. There is a C-H⋯π contact between the naphthalene rings and π-π contacts between the naphthalene rings and the naphthalene and benzene rings [centroid-centroid distances = 3.651 (1), 3.828 (1), 3.811 (2) and 3.786 (1) Å].

3,6-Bis(3,4,5-trimethoxy-phen-yl)-1,2,4-triazolo[3,4-b][1,3,4]thia-diazole.

In the mol-ecule of the title compound, C(21)H(22)N(4)O(6)S, the planar central heterocyclic ring system is oriented with respect to the trimethoxy-phenyl rings at dihedral angles of 2.60 (5) and 3.60 (6)°. Intra-molecular C-H⋯N and C-H⋯S hydrogen bonds result in the formation of planar five- and six-membered rings. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules. There is a C-H⋯π contact between a methyl group and a trimethoxy-phenyl ring, and a π-π contact between the central heterocyclic ring system and a trimethoxy-phenyl ring [centroid-centroid distance = 3.640 (1) Å].

N-(5-Chloro-3-methyl-1-phenyl-pyrazol-4-ylcarbon-yl)-N'-(2-methoxy-phen-yl)thio-urea.

In the title compound, C(19)H(17)ClN(4)O(2)S, the dihedral angle between the pyrazole and phenyl rings is 43.3 (3)°. The bridging unit between the pyrazole and methoxyphenyl rings is planar within 0.0169 Šand makes dihedral angles of 2.3 and 26.4°, respectively, with these two rings. This conformation is influenced by intramolecular N-H⋯O and N-H⋯Cl hydrogen bonds. The crystal packing is stabilized by C-H⋯π inter-actions.

N-(5-Chloro-3-methyl-1-phenyl-1H-pyrazol-4-ylcarbon-yl)-N'-(2,6-dimethyl-phen-yl)thio-urea.

In the title compound, C(20)H(19)ClN(4)OS, the pyrazole ring makes dihedral angles of 89.2 (4) and 46.4 (4)° with the phenyl and substituted benzene rings, respectively; these two six-membered rings are twisted by 52.1 (4)° with respect to each other. There are intra-molecular hydrogen bonds of types N-H⋯O and N-H⋯Cl.

Good laboratory practices guarantee biosafety in the Sierra Leone-China friendship biosafety laboratory.

BACKGROUND: The outbreak of Ebola virus disease (EVD) in West Africa between 2014 and 2015 was the largest EDV epidemic since the identification of Ebola virus (EBOV) in 1976, and the countries most strongly affected were Sierra Leone, Guinea, and Liberia. FINDINGS: The Sierra Leone-China Friendship Biological Safety Laboratory (SLE-CHN Biosafety Lab), a fixed Biosafety Level 3 laboratory in the capital city of Sierra Leone, was established by the Chinese government and has been active in EBOV detection since 11 March 2015. Complete management and program documents were created for the SLE-CHN Biosafety Lab, and it was divided into four zones (the green, yellow, brown, and red zones) based on the risk assessment. Different types of safe and appropriate personnel protection equipment (PPE) are used in different zones of the laboratory, and it fully meets the Biosafety Level 3 laboratory standards of the World Health Organization. CONCLUSION: Good preparedness, comprehensive risk assessment and operation documents, appropriate PPE, effective monitoring and intensive training, together with well-designed and reasonable laboratory sectioning are essential for guaranteeing biosafety.

[Increased resistance against oxidant-induced injury in the rat vascular smooth muscle cells transfected with human heme oxygenase-1 gene].

The heme oxygenase-1 (HO-1), a rate-limiting enzyme in heme metabolism, has been recently defined as a novel stress-stimulated protein, since the intracellular expression of HO-1 in response to various stimuli as oxidation, ischemia and endotoxin injury has been proved to be able to protect the cells from damage. In this study, a retroviral vector containing human HO-1 gene was constructed and transfected to rat vascular smooth muscle cells (VSMCs). Using Southern and Northern blot analyses, the integration and mRNA expression of HO-1 gene in the transfected cells were confirmed. The profound protein expression of HO-1 as well as HO enzyme activity in the transfected cells increased by 1.8-fold and 2.0-fold respectively as compared with the non-transfected cells. It was found that the HO-1 transfected-VSMCs presented dominant resistance to toxicity produced by exposure to H2O2, as a significant protective effect of HO-1 marked by cell survival and LDH leakage was observed when 200, 400 and 600 micromol/L of H2O2 were used. The protection of HO-1 rapidly declined after the transfected-VSMCs were pretreated 24 h with an HO-1 specific inhibitor (ZnPP-IX). The results of this investigation suggest that the functional expression of HO-1 gene within VSMCs raises an alternative ability to protect the vascular cells against active oxygen injury.

[Prokaryotic expression and purification of human hepatic stimulator substance].

To explore the possibility of prokaryotic expression of human hepatic stimulator substance (hHSS), hHSS gene was inserted in the downstream of glutathion S-transferase (GST) in a pET-42a expression vector and recombinant GST-hHSS fusion protein was expressed under IPTG induction in BL-21(DE3) cells. The recombinant HSS was purified with His.Tag affinity chromatography, and its bioactivity was analyzed. The results showed that GST-hHSS fusion protein was expressed both as a soluble or a inclusive body in bacterial cytosol. The soluble GST-hHSS expression reached up to 30% of the whole soluble protein of bacteria as determined by densitometry. The cleavage of GST-hHSS fusion protein with Factor Xa produced two fragments of the protein, which sized 33 and 15 kD, respectively. The molecular weight of recombinant HSS protein was identical to theoretical deduction based on the DNA sequences. The protein homology of 15 kD hHSS could be efficiently eluted out after Factor Xa cleavage. It is further indicated that the recombinant hHSS is able to proliferate hepatoma cells of BEL-7402 in the preliminary experiments.

[Transfection of human hepatic stimulator substance gene could protect BEL-7402 cells against hepatotoxins].

OBJECTIVE: To investigate protective effects of hHSS transfection against CCl4 or H2O2. METHODS: cDNA coding for hHSS was constructed into eukaryotic vector of pcDNA3.1 and transfected into BEL-7402 hepatoma cells. The expression of hHSS was analyzed with Northern blot. RESULTS: The growth of the hepatoma cells was remarkably enhanced 24 to 144h after hHSS gene transfection, which suggesting hHSS gene expression could stimulate cells activity. Meantime, incubation of both wild-type and vector-transfected as well as hHSS-transfected cells with CCl4 or H2O2 resulted in severe damage as marked by cell mortality and the rate of apoptosis. However, it appeared that the transfection of hHSS enabled the hepatoma cells to raise obvious resistance against CCl4 and H2O2 injury. Compared the vector cells to the vector-transfected cells, apoptosis ratio were (32.44+/-0.52)% and (25.60+/-0.66)% in which treated with CCl4, while (47.78+/-0.45)% and (37.40+/-0.69)% in which treated with H2O2, t value is 16.82 and 25.20, P<0.01. MAPK phosphorylation was also activated after HSS transfected. CONCLUSION: The function of hHSS gene expression could be related to proliferation of cell and protection against free radical damage.

[Construction and immunological responses of recombinant adenovirus containing Epstein-Barr nuclear antigen 1 in mice].

This study aimed to construct recombinant adenovirus expressing Epstein-Barr nuclear antigen 1 (EBNA1) against nasopharyngeal carcinoma (NPC). The C-terminal region fragment of the ebna1 gene of Epstein-Barr virus was amplified from the standard strain B95-8 by polymerase chain reaction (PCR). The gene fragment was inserted into the pDC316 shuttle plasmid using the EcoRI and BgIII restriction enzyme sites. The pDC316-ebna1 shuttle plasmid and pBHG helper plasmid were cotransfected into HEK293 cells after sequencing. The soluble protein was extracted from HEK293 cells, which caused apparent cytopathic effects. The transcription and expression of the ebna1 gene were confirmed using flow cytometry and Western blotting. rAd-ebna1 titers were measured by the TCID50. rAd-ebna1 was injected into BALB/c mice at a dose of 2 x 10(8) VP per mouse, EBNA1 epitope-specific responses were measured at 1st, 2nd, 4th and 8th weeks post-immunization. The target fragment of ebna1 (939 bp) was obtained by PCR, and was in consensus with the sequence from the standard strain B95-8. Cytopathic effects were observed after the pDC316-ebna1 shuttle plasmid and pBHG helper plasmid were cotransfected into HEK293 cells. rAd-ebna1 was successfully recombined in HEK293 cells. EBNA1 protein was detected in HEK293 cells, rAd-ebna1 titers reached 10(8) TCID50/mL. Specific responses to CD4+ epitopes of EBNA1 were detected in the immunized mice. In conclusion, rAd-ebna1 was successfully constructed and induced specific responses to CD4+ epitopes of EBNA1 in immunized mice.

[Expression and purification of EBV-LMP2 protein].

OBJECTIVE: To obtain a second Epstein-Barr virus membrane protein (LMP2) in insect cells. METHODS: The full length EBV-LMP2 gene was inserted into baculovirus expression transfer vector pFastBac HT B to obtain the recombinant baculoviruses Bac-LMP2. And generation of recombinant baculoviruses was followed by transfection of the recombinant Bac-LMP2 into insect cells, then the recombinant LMP2 protein was recognized by SDS-PAGE and western blot. The expressed LMP2 protein was purified by one step with Ni-NTA metal chelation chromatography. RESULTS: The expressed LMP2 protein was confirmed by SDS-PAGE and western blot. The purity of purified LMP2 protein is up to 86% by HPLC analysis. CONCLUSION: The EBV-LMP2 was expressed in insect cells, and the purified LMP2 protein was obtained.