Nutrients recovery by coupled bioreactor of heterotrophic ammonia assimilation and microbial fuel cell in saline wastewater

Heterotrophic ammonia assimilation (HAA) process had been widely used in the treatment of high salt wastewater, but the electro enhanced coupling process and electron transfer process were rarely studied. In this study, a HAA process coupled microbial fuel cell (MFC) system was established to treat ammonia-containing wastewater under increasing salinity to achieve nitrogen recovery and electricity generation. Up to 95.4 % NH4+-N and 96.4 % COD removal efficiencies were achieved at 2 % salinity in HAA-MFC. The maximum power density and current density at 2 % salinity were 29.93 mW/m2 and 182.37 mA/m2, respectively. The residual organic matter in the cathode effluent was effectively removed by the anode. The increase of salinity not only enhanced the sludge settling performance and activity, but also promoted the enzyme activity and amino acid production of the ammonia assimilation pathway. Marinobacter and Halomonas were gradually enriched at the anode and cathode with increased salinity to promote ammonia assimilation and electron production. This research offered a promising solution to overcome salinity-related challenges in wastewater treatment and resource recovery.

Novel strategy for treating high salinity oilfield produced water: Pyrite-activated peroxymonosulfate coupled with heterotrophic ammonia assimilation

Existing conventional biological treatment techniques face numerous limitations in effectively removing total petroleum hydrocarbons (TPHs) and ammonia (NH4+-N) from oilfield-produced water (OPW), highlighting the pressing need for innovative pre-oxidation and biological treatment processes. In this study, a pyrite-activated peroxymonosulfate (PMS)-coupled heterotrophic ammonia assimilation (HAA) system was established to achieve satisfactory system performance for OPW treatment. Pyrite sustained-release Fe2+-activated PMS was used to produce SO4•- and •OH, and 71.0 % of TPHs were effectively removed from the oil wastewater. The average TPHs and NH4+-N removal efficiencies in the test group with pre-oxidation were 96.9 and 98.3 %, compared to 46.5 and 77.1 % in the control group, respectively. The maximum fluorescence intensities of tryptophan protein and aromatic protein in the test group declined by 83.7 %. Fourier transform ion cyclotron resonance mass spectrometry revealed that pre-oxidation degraded more long-chain hydrocarbons and aromatic family compound, whereas the HAA process produced more proteins and carbohydrates. Pyrite-PMS promoted the enrichment of ammonia-assimilating bacteria, alleviating the explosive increase in extracellular polymeric substances and reducing sludge settleability. The low cost, efficiency, green chemistry principles, and synergies of this approach make it a powerful solution for practical OPW treatment to reduce environmental impacts and promote sustainable wastewater treatment.

Enhanced degradation of petroleum in saline soil by nitrogen stimulation and halophilic emulsifying bacteria Bacillus sp. Z-13

Remediation of petroleum-contaminated soil is a widely concerned challenge. As an ecofriendly method, the performance improvement of indigenous microbial degradation is facing the bottleneck. In this study, a strain with high efficiency of petroleum degradation was isolated from the petroleum-contaminated soil and identified and named as Bacillus sp. Z-13. The strain showed the ability to produce lipopeptide surfactant which could improve 66% more petroleum hydrocarbons eluted. Strain Z-13 and its biosurfactant exhibited broad environmental adaptability to salinity (0-8%), pH (6-9) and temperature (15-45 °C). With the addition of strain Z-13 and the stimulation of NH4Cl, up to 59% of the petroleum in the contaminated soil was removed at the carbon to nitrogen ratio of 10. Microbial community analysis showed that petroleum-degrading bacteria, represented by Bacillus, became the dominant species at genus level and played an important role in the remediation. Additionally, ammonium stimulation facilitated both pathways of ammonium assimilation and nitrification in native microorganisms to achieve efficient degradation of petroleum hydrocarbons. This study could provide a promising approach for stable, environmental-friendly and efficient remediation of petroleum-contaminated soil.

Mortality risk of COVID-19 in elderly males with comorbidities: a multi-country study

The COVID-19 pandemic causes severe morbidity and mortality. This multi-country study aimed to explore risk factors that drive mortality in COVID-19 patients who received neither dexamethasone nor remdesivir. We analyzed a cohort of 568 survivors and 507 non-survivors from China, European regions, and North America. Elderly males ≥70 years accounted for only 25% of survivors, but this rate was significantly higher in non-survivors from China (55%), European regions (63%), and North America (47%). Compared with survivors, non-survivors had more incidences of comorbidities such as cerebrovascular disease and chronic obstructive pulmonary disease (COPD, p-values<0.05). Survival analyses revealed age, male gender, shortness of breath, cerebrovascular disease, and COPD as mortality-associated factors. Survival time from symptom onset was significantly shorter in elderly versus young patients (median: 29 versus 62 days), males versus females (median: 46 versus 59 days), and patients with versus without comorbidities (mean: 41 versus 61 days). Mortality risk was higher in elderly males with comorbidities than in young females without comorbidities (p-value<0.01). Elderly male survivors with comorbidities also had longer hospital stays than other survivors (25 versus 18.5 days, p-value<0.01). Overall, the high mortality risk in elderly males with COVID-19-associated comorbidities supports early prevention and critical care for elderly populations.

CAT1 silencing inhibits TGF-β1-induced mouse hepatic stellate cell activation in vitro and hepatic fibrosis in vivo

Hepatic fibrosis is characterized by abnormal accumulation of extracellular matrix (ECM). Hepatic stellate cells (HSCs) are the primary cells that produce ECM in response to hepatic injury, and transforming growth factor-beta (TGF-β) has been regarded as the central stimulus responsible for HSC-mediated ECM production. In the present study, we attempted to identify a critical factor in HSC activation and the underlying mechanism. By analyzing online microarray expression profiles, we found that the expression of high-affinity cationic amino acid transporter 1 (CAT1) was upregulated in hepatic fibrosis models and activated HSCs. We isolated and identified mouse HSCs (MHSCs) and found that in these cells, CAT1 was most highly upregulated by TGF-β1 stimulation in both time- and dose-dependent manners. In vitro, CAT1 overexpression further enhanced, while CAT1 silencing inhibited, the effect of TGF-β1 in promoting MHSC activation. In vivo, CAT1 silencing significantly improved the hepatic fibrosis induced by both CCl4 and non-alcoholic fatty liver disease (NAFLD). In summary, CAT1 was significantly upregulated in TGF-β1-activated MHSCs and mice with hepatic fibrosis. CAT1 silencing inhibited TGF-β1-induced MHSC activation in vitro and fibrogenic changes in vivo. CAT1 is a promising target for hepatic fibrosis treatment that requites further investigation in human cells and clinical practice.

Clinical characteristics of older and younger patients infected with SARS-CoV-2

Background: SARS-CoV-2 causes high mortality risk in older patients. This study aims to characterize the clinical features of older and younger SARS-CoV-2 infected patients.

Results: A total of 239 patients were divided into the younger group (<60 years; n=181) and the older group (≥60 years; n=58). In both groups, fever and cough were common symptoms. However, dyspnea was more frequent in older patients than younger patients (20.7% versus 9.9%, p=0.032). Compared with younger patients, older patients harbored more severe cases (37.9% versus 17.1%, p=0.001) and comorbidities (58.6% versus 21.0%, p<0.001) such as hypertension and diabetes. The baseline values of eosinophils and C-reactive protein were abnormal in older and younger groups. From baseline to day 14, significant decreases of three biomarkers (C-reactive protein, hemoglobin, albumin) and dramatic increases of three biomarkers (lymphocytes, platelets, blood urea nitrogen) were observed in older patients.

Conclusion: Older and younger patients exhibited differences in dyspnea, comorbidities, and proportions of severe cases. Moreover, the disease progression of SARS-CoV-2 in older patients is observed with the dynamics of laboratory biomarkers, supporting their potential use in disease monitoring.

Methods: We retrieved clinical symptoms, laboratory findings, comorbidities, and hospitalization information of SARS-CoV-2 cases in Changsha.

Palladium-catalyzed synthesis of polysubstituted quinolines from 2-amino aromatic ketones and alkynes

A palladium-catalyzed one-pot method for the synthesis of quinolines from commercial or readily available 2-amino aromatic ketones and alkynes is reported for the first time.

Knockdown of HBx by RNAi inhibits proliferation and enhances chemotherapy-induced apoptosis in hepatocellular carcinoma cells

The present study was designed to research on RNA interference hepatitis B virus x gene approach to hepatocellular carcinoma (HCC) therapy. Previously, we constructed and identified shRNA eukaryotic expression vectors (pshRNA-X220) specific to HBx gene, pshRNA-MOCK (control); and established HCC cell lines with stable expression shRNA eukaryotic vector targeting HBx gene-21543 cell lines (MHCC97-H of expressing shRNA against HBx), HK3 cell lines (MHCC97-H by transfected with pshRNA-MOCK). We examined the expression of HBx gene after RNA interference by semi-quantitative RT-PCR and assessed the effect of HBx knocked down on cell growth by proliferation assay using kit-8 (CCK8). As well as, we analyzed cell cycle distribution by flowcytometry and examined cell apoptosis using TUNEL assay. The HBx mRNA expression level is reduced, and cells growth was significantly stopped in 21543 cell lines. Cells with HBx knockdown were more sensitive to 5-fluorouracil/cisplatin. RNA interfering HBx induced an obvious time and dose-dependent inhibitory in comparison with the control cells. Meanwhile, RNA interferenced targeting HBx, in combination with chemotherapy can effectively induce apoptosis in hepatocellular carcinoma cells and restricts cell proliferation.

[Effect of HBx gene RNA interference combined with chemotherapy on hepatocellular carcinoma cells]

OBJECTIVE

To determine the influence of HBx gene RNA interference combined with chemotherapy on stable hepatocellular carcinoma cells growth and its apoptosis mechanism.

METHODS

Stable hepatocellular carcinoma cells transfected by shRNA aiming at HBx together with independent control series (MHCC97-H,HK3, and 21543) were identified. The extent of HBx gene by RNA interference was detected by RT-PCR. The influence of cell growth through RNA interference was observed with cell counting kit-8 (CCK8), the diversity of cell cycle by flow cytometry and cell apoptosis were detected by TUNEL apoptosis detection kit.

RESULTS

RT-PCR demonstrated that the HBx mRNA level of 21,543 cell down regulation was 91%. The HBx mRNA level of HK3 cells was not different from MHCC97-H cell. The growth of 21,543 cells was obviously slower than MHCC97-H cells and HK3 cells, with no significant difference. The cell cycle of 21,543 cells showed that hepatocellular carcinoma cells through RNA interference targeting at HBx delayed in go to S stage, and the proliferation activity degraded obviously. The 3 kinds of cells adding different concentrations of flurouracil and cisplatin grew slowlier than the origin cells. The growth inhibition was dependent on the concentration of drug with growth inhibition of 21,543 cells the most obvious.That of the 3 kinds of cells adding alpha-interferon was not obvious.Flurouracil induced apoptosis in all cells. Apoptosis in 21,543 cells was the most obvious.

CONCLUSION

RNA interference targeting at HBx can suppress the growth of hepatocellular carcinoma cells. Hepatocellular carcinoma cells through RNA interference targeting at HBx can intensify chemo-sensitivity. Combination of RNA interference targeting at HBx with chemotherapeutics can induce apoptosis in more hepatocellular carcinoma cells and cell proliferation steps down accordingly.

[Clinical character and therapeutic effect of late-onset Wilson disease]

OBJECTIVE

To investigate the clinical character and therapeutic effect of late-onset Wilson disease,and to provide some evidence for its diagnosis and treatment.

METHODS

Clinical character, changes of copper metabolism, and therapeutic effect of 8 patients with late-onset Wilson disease were analyzed. Ceruloplasmin level was measured by nephelometry, and the copper contents in the serum, urine, and liver were measured by flame atomic absorption spectroscopy. The initial treatment was sodium dimercaptosulphonate, followed by D-penicillamine and/or zinc.

RESULTS

Patients with late-onset Wilson disease accounted for 7.0% of all patients, Who presented liver disease symptoms such as loss of appetite or nausea at the early stage and were misdiagnosed easily. Their blood routine and aminotransferase levels were normal in most patients with late-onset Wilson disease, and all patients had Kayser-Fleisher rings. There was significant difference between the liver function and copper metabolite test. The average urinary copper content was 4 072 microg/24 h on the first day after administrating sodium dimercaptosulphonate, which was 18.1 times as much as that before the treatment, and 2.5 times as much as that of D-penicillamine. No obvious adverse reactions were observed. The prognosis was usually good.

CONCLUSION

Enough attention should be paid to late-onset Wilson disease which is not rare and easy to be misdiagnosed. Good response can be expected in patients treated with sodium dimercaptosulphonate in the initial stage.

Effects of HBV X gene and arsenic trioxide on the expression of p53 in cultured HepG2 cells

BACKGROUND

Hepatitis B virus (HBV) X protein (HBx) and p53 could mutually down-regulate at transcriptional level and HBx could bind with p53 protein within its transactivation domain and inhibit the function of p53 protein. In recent years, effects of arsenic trioxide (As2O3) on the expression of p53 protein have been widely studied, while little is known about the activity of p53 protein. This study was undertaken to delineate the effect of HBV X gene and As2O3 on p53 protein expression (level and activity) in HepG2 cells by small hairpin RNA (shRNA)-mediated RNA interference (RNAi) technique.

METHODS

Cell line HepG2 and cells with stable expression of HBV X gene (HepG2-X) were treated with 2 micromol/L As2O3, with corresponding untreated cells serving as controls. Cell lysates and nuclear extracts were extracted. Total level and the relative activity of p53 protein were detected by modified enzyme-linked immunosorbent assay (ELISA). HBV X gene sequence-specific shRNA expression vector (pXi-1 and pXi-2) and sequence-unrelated control (pXi-3) were transfected into HepG2-X. Single cell clone with stable expression of shRNA was selected and exposed to propagating culture. The effect of As2O3 on p53 protein expression and activity was re-observed.

RESULTS

Total p53 protein level was up-regulated and its relative activity ratio was enhanced by As2O3 in HepG2 and HepG2-X cells. The total p53 protein level induced by As2O3 was up-regulated by HBV X gene expression, while its relative activity was significantly suppressed. The suppression was removed after HBV X gene expression was repressed by shRNA.

CONCLUSIONS

As2O3 up-regulates p53 protein expression and enhance its activity. HBV X up-regulates As2O3 induced-p53 protein expression while suppresses its activity.

[Serum HBsAg concentration and HBV replication level in hepatitis B patients with positive serum HBsAg and HBeAg]

OBJECTIVE

To analyze the relationship between serum HBsAg concentration and HBV replication level in hepatitis B patients with positive serum HBsAg and HBeAg, and to explore the possibility of using serum HBsAg concentration as a marker of HBV replication level in hepatitis B patients with positive serum HBeAg.

METHODS

HBV DNA level and serum HBeAg, HBsAg concentration of 296 patients with positive serum HBsAg and HBeAg were quantitatively detected by real-time fluorescence quantitative PCR (FQ-PCR) and time-resolved fluoroimmunoassay (TRIFA) respectively. HBsAg concentrations were compared among patients with different HBV DNA levels, and HBV DNA levels were compared among patients with different HBsAg concentrations. The correlation between serum HBsAg concentration and DNA replication level were analyzed. The positive, negative predictive values and coincidence rates were speculated by various HBsAg concentrations.

RESULTS

If HBV DNA positive was defined as HBV DNA levels no less than 10(5) copy/mL, then 228(77.03%) patients were classified as HBV DNA positive. HBsAg concentration was positively correlated with HBV DNA replication level, but among groups with various DNA replication levels, HBsAg concentration showed no significant statistical difference (P>0.05). If the patients were divided into 2 groups, HBsAg concentration (180 microg/L) was served as the cutoff level, the DNA positive rate of the group with HBsAg concentration no less than 180 microg/L was significantly higher than that with HBsAg concentration less than 180 microg/L (chi(2)=3.998, P<0.05). DNA positive rates and average DNA levels showed no significant statistical differences between the 2 groups, if HBsAg concentrations other than 180 microg/L were used as the cutoff level. Positive predictive values, negative predictive values and the coincidence rates speculated by various HBsAg concentrations as cutoff values did not show any significant statistical difference in estimating HBV replication levels.

CONCLUSION

To some extent, serum HBsAg concentration is related to HBV DNA replication level in hepatitis B patients with positive serum HBsAg and HBeAg, but it is not feasible to use HBsAg concentration to monitor their HBV replication levels.

[Construction of two hepatocellular carcinoma cell models for the expression of HBV X gene with different selection characteristics]

OBJECTIVE

To construct 2 hepatocellular carcinoma (HCC) cell models for the expression of HBV X gene with different selection characteristics.

METHODS

HepG2 HCC cells were infected with eukaryotic expression vectors with HBV X gene, pCEP4-X, and pcDNA3. 1 (+)-X. Single cell clone was selected by hygromycin and neomycin. After propagating culture for certain periods, the HBV X gene expression was identified by PCR, RT-PCR, and Western blot.

RESULTS

Single HCC cell clone with HBV X gene transferred resistant to hygromycin and neomycin was selectively cultured, and the cells could be propagated for certain periods. PCR, RT-PCR, and Western blot identified the expression of HBV X gene.

CONCLUSION

Two HCC cell models for the expression of HBV X gene with different selection characteristics have been successfully constructed.

[A novel stop codon mutation in S gene: the molecular basis of a patient with cryptogenic cirrhosis]

OBJECTIVE

To explore the pathogen and molecular basis of cryptogenic cirrhosis in a patient.

METHODS

Serum was collected from a patient, male, aged 56, with cryptogenic cirrhosis. HBV serologic markers were qualitatively tested, and HBsAg, HBeAg, and anti-HBc were quantitatively determined again. HBV DNA in serum was qualitatively tested using PCR, and quantified using fluorescence quantitative PCR. S gene was amplified, cloned, and sequenced.

RESULTS

HbsAg and anti-Hbe were negative, and anti-HBs, HBeAg, anti-HBc, and HBV DNA were all positive. HBsAg (S/N) was 0.77 (cutoff of S/N: >/= 2.00), HbeAg (S/N) was 56.43 (cutoff of S/N: >/= 2.10), anti-HBc (S/C(O)) was 0.03 (cutoff of S/C(O): </= 1.00); HBV DNA was 1.54 x 10(9) copies/ml. An uncommon point mutation at nucleotide 336 (C to A) in S gene was found, resulting in the change of the 61st codon into a novel stop codon and failure of synthesis of HbsAg.

CONCLUSION

HBV proves the pathogen of this case. This special mutation well explains the patient's unusual serologic pattern. Moreover, this finding possesses important clinical and theoretical significance.