Antioxidant CeO2 doped with carbon dots enhance ammonia production by an electroactive Azospirillum humicireducens SgZ-5T

Microbial nitrogen fixation is a fundamental process in the nitrogen cycle, providing a continuous supply of biologically available nitrogen essential for life. In this study, we combined cerium oxide-doped carbon dots (CeO2/CDs) with electroactive nitrogen-fixing bacterium Azospirillum humicireducens SgZ-5T to enhance nitrogen fixation through ammonium production. Our research demonstrates that treatment of SgZ-5T cells with CeO2/CDs (0.2 mg mL-1) resulted in a 265.70% increase in ammonium production compared to SgZ-5T cells alone. CeO2/CDs facilitate electron transfer in the biocatalytic process, thereby enhancing nitrogenase activity. Additionally, CeO2/CDs reduce the concentration of reactive oxygen species in SgZ-5T cells, leading to increased ammonium production. The upregulation of nifD, nifH and nifK gene expression upon incorporation of CeO2/CDs (0.2 mg mL-1) into SgZ-5T cells supports this observation. Our findings not only provide an economical and environmentally friendly approach to enhance biological nitrogen fixation but also hold potential for alleviating nitrogen fertilizer scarcity.

[Analysis of 6 cases with hepatocerebral mitochondrial DNA depletion syndrome and literature review]

Objective: To explore the clinical features of hepatocerebral mitochondrial DNA depletion syndrome (MDS). Methods: The clinical data of 6 hepatocerebral MDS patients diagnosed in the Jinshan Hospital of Fudan University from January 2012 to December 2019 were retrospectively collected and analyzed. Related literature published before January 2020 were searched with the key words of "DGUOK""MPV17""POLG""C10orf2" in PubMed, China national knowledge infrastructure (CNKI) and Wanfang database. Results: All the 6 hepatocerebral MDS cases were male. The age of onset ranged from 3 days to 8 months. The most common initial symptoms were cholestasis and developmental retrogression. The main clinical manifestations included hepatomegaly (4 cases), hypotonia (3 cases), growth retardation (4 cases), cholestasis (5 cases), coagulopathy (5 cases), hypoalbuminemia (3 cases), hypoglycemia (4 cases), hyperlactacidemia (5 cases), and abnormal blood metabolism screening (6 cases). The isotope hepatobiliary imaging revealed no gallbladder and intestinal tract development within 24 hours in 2 patients. Regarding the cranial imaging examination, the head CT found widening of the extracranial space in 1 case, the brain magnetic resonance imaging (MRI) found ventricular enlargement in 2 cases, and the brain ultrasound found peripheral white matter injury in 1 case. Two cases were lost to follow-up, one died of liver failure, and three died of multiple organ failure due to aggravated infection. Among the 6 cases, there were 3 with MPV17 variation (c.182T>C and c.279G>C were novel), 1 with POLG variation (c.2993G>A was novel), 1 with DGUOK variation (c.679G>A homozygous mutation, parthenogenetic diploid of chromosome 2) and 1 with C10orf2 variation (c.1186C>T and c.1504C>T were novel). The literature review found that 129, 100, 51 and 12 cases of hepatocerebral MDS were caused by DGUOK, MPV17, POLG and C10orf2 gene variations, respectively. And the most common clinical manifestations were liver dysfunction presented with cholestasis and elevated transaminase, metabolic disorders including hypoglycemia and hyperlactacidemia, and diverse neurologic symptoms including developmental retardation, hypotonia, epilepsy and peripheral neuropathy. Besides, 1/3 of the patients with C10orf2 variation developed renal tubular injury. Conclusions: Hepatocerebral MDS mainly present with liver dysfunction, metabolic disorder and neuromuscular impairment. Different genotypes show specific clinical manifestations.

Facile synthesis of magnetic molybdenum disulfide@graphene nanocomposite with amphiphilic properties and its application in solid-phase extraction for a wide polarity of insecticides in wolfberry samples

A novel magnetic molybdenum disulfide@graphene (Fe₃O₄/MoS₂@G) nanocomposite with amphiphilic properties was prepared via a co-mixing solvothermal method. To demonstrate the feasibility of Fe₃O₄/MoS₂@G as a sorbent during sample preparation, it was employed for the magnetic solid phase extraction (MSPE) of ten pyrethroids, three triazoles and two acaricide pyridaben and picoxystrobin in an emulsified aqueous solution. Dichloromethane was used as the extractant to form an emulsified aqueous solution. Subsequently, the Fe₃O₄/MoS₂@G sorbent with amphiphilic properties was used to retrieve 15 wide polarity insecticides from dichloromethane via MSPE. The proposed method has the advantage of being applicable to different polar pesticides, strengthening the capacity of enrichment and purification of target analytes. The π-π interaction between the hydrophilic and hydrophobic moieties of Fe₃O₄/MoS₂@G and the aromatic rings of target analytes were responsible for the efficient sorption. Thus, a reliable, convenient, and efficient method for the analysis of 15 insecticides with wide polarity in wolfberry samples was established by coupling Fe₃O₄/MoS₂@G nanocomposite MSPE with gas chromatography-mass spectrometry (GC-MS) analysis. The obtained linearity of this method was in the range from 1 to 5000 ng mL^-1 for 15 analytes, with determination coefficients (R²) ≥0.9907. The limit of detection (LOD) for 15 insecticides was in the range from 0.1 to 5.0 ng g^-1. The recoveries of 15 insecticides from spiked wolfberry samples were in the range from 71.41% to 110.53%, and RSD was less than 14.8%.

Long non-coding RNA GAS5 promotes natural killer cell cytotoxicity against gastric cancer by regulating miR-18a

Natural killer (NK) cells play significant roles in spontaneous antitumor response in multiple cancers, including gastric cancer. Currently, lncRNAs were identified as essential modulators in the development of NK cells via competing for the target miRNA. However, the regulatory mechanism of GAS5 in NK cells remains largely elusive. The expressions of GAS5 and miR-18a in NK cells were measured by qRT-PCR. The killing effects of NK cells were conducted by lactate dehydrogenase (LDH) assay. Detection of IFN-γ and TNF-α level was carried out using ELISA assay. The interaction between GAS5 and miR-18a was determined by the luciferase reporter system and RIP assay, respectively. We found that GAS5 expression was downregulated while miR-18a expression was upregulated in primary NK cells isolated from GC patient compared with the healthy controls. Moreover, activation of NK cells stimulated by IL-2 enhanced the secretion of IFN-γ, TNF-α, and the expression of GAS5. The deficiency of GAS5 significantly suppressed the secretion of IFN-γ and TNF-α as well as the killing effect of NK cells. Subsequently, luciferase reporter and RIP assay confirmed the interaction between GAS5 and miR-18a. In addition, miR-18a inhibitor attenuated GAS5 silencing induced inhibition of the cytotoxicity of activated NK cells. In conclusion, GAS5 promotes the killing effect of the natural killer cells against GC by regulating miR-18a, providing promising strategies for NK cells based antitumor therapies.

Intracellular catalase activity instead of glutathione level dominates the resistance of cells to reactive oxygen species

Artesunate (ARS) induced significant reactive oxygen species (ROS) generation in HepG2, HeLa, and A549 lines. However, ARS induced ROS-dependent apoptosis in HeLa and A549 cell lines but ROS-independent apoptosis in HepG2 cells. A total of 200 μM hydrogen peroxide (H2O2) significantly induced cytotoxicity in HeLa cells, while H2O2 up to 300 μM did not induce cytotoxicity in HepG2 cells, further demonstrating the strong resistance of HepG2 cells to ROS. HeLa cells had much higher basic total glutathione (T-GSH) level than HepG2 cells, while the ratio of basic reduced glutathione (GSH)/oxidized glutathione (GSSG) in HepG2 cells was nearly twice than that in HeLa and A549 cells. Inhibition of glutathione markedly enhanced H2O2- or ARS-induced cytotoxicity in HeLa and A549 cell lines but modestly enhanced the cytotoxicity of H2O2 and even did not affect the cytotoxicity of ARS in HepG2 cells. Moreover, addition of GSH remarkably prevented H2O2- or ARS-induced cytotoxicity in HeLa and A549 cell lines, further indicating the involvement of GSH in scavenging ROS in the two cell lines. HepG2 cells exhibited higher catalase activity than HeLa cells, and inhibiting catalase activity by using 3-aminotriazole (3-AT, a specific inhibition of catalase) or catalase siRNA remarkably reduced the resistance of HepG2 cells to ROS, demonstrating the key roles of catalase for the strong resistance of HepG2 cells to ROS. Collectively, catalase activity instead of glutathione level dominates the resistance of cells to ROS.

[Effect of skin soft tissue expansion on repair of large area of scars on extremities]

Objective: To investigate the effect of skin soft tissue expansion on repair of large area of scars on extremities. Methods: Twenty-five patients with large area of scars on extremities were admitted to our department from June 2007 to October 2014. There were 14 males and 11 females, aged 4 to 36 years. Operations were performed under local infiltration anesthesia or general anesthesia. In the first stage, 1 to 5 cylindrical expanders with capacities of 250 to 600 mL were placed at left or right sides or at upper or lower parts of the scars. In the second stage, scars of 21 patients were repaired with expanded transverse propulsive and lateral flaps, and scars of 4 patients were repaired with expanded perforator flaps whose pedicles were perforators of brachial artery, superior ulnar collateral artery, or posterior interosseous artery according to areas and shapes of the scars. The secondary wound areas ranged from 13 cm×7 cm to 34 cm×18 cm after dissolution or excision of scars. The areas of flaps ranged from 13 cm×7 cm to 20 cm×12 cm. The donor sites were sutured directly. The flaps after operation and follow-up of patients were observed and recorded. Results: All expanded flaps survived after operation. And the superficial distal part of flap whose pedicle was perforator of posterior interosseous artery in one patient was with necrosis, and other flaps survived well. During follow-up of 3 to 15 months after operation of the second stage, color and texture of flaps were similar to surrounding skin, while extremities of donor sites were thinner and auxiliary incisional scars formed after expansion. Conclusions: Expanded flap is a good way to repair large area of scar on extremities. Bilateral skin of scar is the first choice of donor site of expanded flap. If there isn't enough skin for expanding on bilateral sides, expanded perforator flap designed at upper or lower part of the scar is another choice to repair the scar.

[A cohort study on the association between fasting plasma glucose level over 5.3 mmol/L and risks of abnormal glucose metabolism and cardiovascular diseases in the elderly]

OBJECTIVE

The aim of the study was to evaluate the association of fasting plasma glucose (FPG) level over 5.3 mmol/L to the development of abnormal glucose metabolism and cardiovascular diseases (CVD).

METHODS

This was a retrospective cohort study with 1 064 non-diabetic subjects(980 males; 84 females) aged 60 or over, who carried out annual health check-up in Chinese PLA General Hospital from May, 1996 to May, 2015. Based on the average FPG level of 3 years before enrollment, the subjects were divided into four groups: <5.3 mmol/L, 5.3-<5.6 mmol/L, 5.6-<6.1 mmol/L and 6.1-<7.0 mmol/L. Glucose metabolic changes, complications and mortality were follow-up until May, 2015.

RESULTS

(1)The initial 3-year average FPG levels were (4.9±0.4) mmol/L in the total 1 064 subjects. Among them, 126 subjects developed diabetes mellitus (DM) and 144 subjects developed impaired glucose regulation (IGR) during the follow-up visits. The proportions of IGR and diabetes increased with the FPG levels (P<0.05). The risk for developing IGR was significantly higher in subjects with FPG≥5.3 mmol/L than in those with FPG <5.3 mmol/L (RR=3.08, 95%CI 2.02-4.81, P<0.01). The risk for incident DM was markedly increased in subjects with FPG ≥ 5.6 mmol/L than in those with FPG <5.6 mmol/L (RR=6.73, 95%CI 3.90-11.52, P<0.01); (2)The risk for CVD was eight folds higher in subjects with FPG ≥5.3 mmol/L than in subjects with FPG <5.3 mmol/L (RR=8.42, 95%CI 5.11-13.82, P<0.05); (3)Survival analysis showed that the risk of death was 1.47 times higher in subjects with FPG ≥5.3 mmol/L than in subjects with FPG <5.3 mmol/L after years of followed-up (RR=1.47, 95%CI 1.09-1.98, P=0.0127).

CONCLUSION

The risks for IGR, CVD and mortality are higher in the elderly with FPG≥5.3 mmol/L, which highlights the importance for the disease prevention in elder people with FPG 5.3 mmol/L or more.

Targeted and controlled drug delivery using a temperature and ultra-violet responsive liposome with excellent breast cancer suppressing ability

Drug delivery systems (DDS) with favorable serum stability, high intra-tumor accumulation and tumor specific drug release are highly desired for promoting chemotherapeutic efficacy.

Coral communities of the remote atoll reefs in the Nansha Islands, southern South China Sea

During the months of May and June in the year 2007, a survey was conducted regarding coral reef communities in the remote atolls (Zhubi Reef and Meiji Reef) of Nansha Islands, southern South China Sea. The goals of the survey were to: (1) for the first time, compile a scleractinian coral check-list; (2) estimate the total richness, coral cover, and growth forms of the community; and (3) describe preliminary patterns of community structure according to geomorphological units. Findings of this survey revealed a total of 120 species of scleractinia belonging to 40 genera, while the average coral cover was 21 %, ranging from less than 10 % to higher than 50 %. Branching and massive corals were also found to be the most important growth forms of the whole coral community, while Acropora, Montipora, and Porites were the three dominant genera in the overall region, with their contributions to total coral cover measuring 21, 22, and 23 %, respectively. Overall, coral communities of the Nansha Islands were in a relative healthy condition with high species diversity and coral cover. Spatial pattern of coral communities existed among various geomorphological units. Mean coral cover was highest in the patch reef within the lagoon, followed by the fore reef slope, reef flat, and lagoon slope. The greatest contributors to total coral cover were branching Acropora (45 %) in the lagoon slope, branching Montipora (44 %) in the reef flat, and massive Porites (51 %) in the patch reef. Coral cover in the fore reef revealed a greater range of genera than in other habitats. The leeward fore reef slope had higher coral cover (> 50 %) when compared with the windward slope (< 10 %). The coral communities of the inner reef flat were characterized by higher coral cover (27 %) and dominant branching Montipora corals, while lower coral cover (4 %) was dominated by Psammocora with massive growth forms on the outer reef flat. Destructive fishing and coral bleaching were two major threats to coral communities in the study area.

Decreased locomotor activity in mice expressing tTA under control of the CaMKII alpha promoter

Transgenic mice in which the tetracycline transactivator (tTA) is driven by the forebrain-specific calcium-calmodulin-dependent kinase II alpha promoter (CaMKII alpha-tTA mice) are used to study the molecular genetics of many behaviors. These mice can be crossed with other transgenic mice carrying a transgene of interest coupled to the tetracycline-responsive promoter element to produce mice with forebrain-specific expression of the transgene under investigation. The value of using CaMKII alpha-tTA mice to study behavior, however, is dependent on the CaMKII alpha-tTA mice themselves lacking a behavioral phenotype with respect to the behaviors being studied. Here we present data that suggest CaMKII alpha-tTA mice have a behavioral phenotype distinct from that of their wild-type (WT) littermates. Most strikingly, we find that CaMKII alpha-tTA mice, both those with a C57BL/6NTac genetic background (B6-tTA) and those with a 129S6B6F1/Tac hybrid genetic background (F1-tTA), exhibit decreased locomotor activity compared with WT littermates that could be misinterpreted as altered anxiety-like behavior. Despite this impairment, neither B6-tTA nor F1-tTA mice perform differently than their WT littermates in two commonly used learning and memory paradigms - Pavlovian fear conditioning and Morris water maze. Additionally, we find data regarding motor coordination and balance to be mixed: B6-tTA mice, but not F1-tTA mice, exhibit impaired performance on the accelerating rotarod and both perform as well as their WT littermates on the balance beam.

[Research on hemostatic mechanism of extracts from carbonized Schizonepeta tenuifolia Brig]

It has been shown that StE can significantly shorten PT, TT, KPTT and RT of experimental animals and has an antiheparin function in the body. Meanwhile, it can significantly shorten ELT and strengthen FA. Its hemostatic action is accomplished through promoting coagulation and inhibiting fibrinolysis. 3P test and EG test were negative, it is thus impossible for a large dosage of StE to lead to DIC.