Sensitive detections for three kinds of vitamin B in aqueous solution and on test paper by fluorescent dual-emission carbon dots.

Although a few of fluorescent probes based on carbon dots (CDs) for vitamin B (VB) determination have been emerged, none of them can realize the detection of different kinds of VB. In this paper, nitrogen, chlorine co-doped dual-emission CDs (N, Cl-CDs) with emissions at 404 nm and 595 nm have been easily synthesized. VB2, VB9 and VB12 can all induce obvious fluorescence turn-off response toward the N, Cl-CDs. Based on that, three types of VBs are quantitatively and sensitively evaluated in aqueous solution with wide concentration ranges of 14.9-135.0 µM, 34.7-89.8 µM and 29.8-79.8 µM, respectively. Importantly, visual semiquantitative detection of VBs on a test strip are also proposed. Moreover, the current N, Cl-CDs have been successfully applied to the detection of VBs in real samples. The N, Cl-CDs are sensitively multifunctional sensors for three kinds of VBs in aqueous solution and the visual semiquantitative detection by test paper assay is simple, portable and inexpensive.

A sensitive sensor based on carbon dots for the determination of Fe3+ and ascorbic acid in foods.

To develop a feasible, sensitive, and essential sensor is important for the identification of Fe3+ ions and ascorbic acid (AA). Herein, highly fluorescent heteroatom co-doped carbon dots (N,S-CDs) with a quantum yield (QY) of 24.6% were synthesized, using hydrothermal treatment of L-cysteine (Cys) and 1-amino-2-naphthol-4-sulfonic acid (ANSA). The fluorescence emission of the as-prepared N,S-CDs was quenched strongly by Fe3+ ions, and this was further recovered by the reduction effect of AA on Fe3+. Based on this, continuous fluorescence sensing of Fe3+ and AA with an "on-off-on" style was developed. The detection of Fe3+ and AA were in relatively wider linear ranges of 5.00-105 µmol L-1 and 4.97-54.8 µmol L-1, with a detection limit of 0.10 µmol L-1 and 2.4 nmol L-1 (S/N = 3), respectively. Then, the N,S-CDs were successfully used to measure Fe3+ ions and AA in some daily food samples, and this method exhibited some advantages over most other reported techniques in the term of response speed, quantum yield, and detection limit.

The Proportion of Vδ1T Cells in Peripheral Blood Correlated with Prognosis of Sepsis.

BACKGROUND: Sepsis is a serious condition with a high mortality rate, and septic patients often have organ dysfunction, low tissue perfusion and hypoxia, lactic acidosis, oliguria, or functional brain changes. OBJECTIVE: To observe the number and the function of Vδ1T cells in peripheral blood of septic patients, to analyze the clinical significance of detecting Vδ1T cells, and to clarify the correlation of their presence with the prognosis of sepsis. METHODS: The basic data of the septic patients were recorded at admission. The immunosuppressive function-related molecules on the surface of Vδ1T cells were detected, and the immunosuppressive function of Vδ1T cells was also evaluated. RESULTS: Compared with the healthy controls, the proportion of Vδ1T cells in the blood of septic patients significantly decreased (P<0.01). The proportion of Vδ1T cells in septic patients correlated with the patients' condition (P<0.05). The expression of glucocorticoid-induced tumor necrosis factor receptor (GITR), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), and T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) on the surface of Vδ1T cells in the blood of septic patients significantly increased (P<0.01). The increase of Vδ1T cells in septic patients had inhibitory effects on T cell proliferation and interferon (IFN)-γ secretion. These findings implied that the immunosuppression of Vδ1Tcells in the peripheral blood of septic patients was significantly higher than that of the healthy controls (P<0.01). CONCLUSION: Changes in Vδ1T cells in septic patients were closely related to the patient's condition and prognosis.

Synthesis of intrinsic dual-emission type N,S-doped carbon dots for ratiometric fluorescence detection of Cr (VI) and application in cellular imaging.

In this paper, intrinsic dual-emission fluorescent carbon dots (CDs) doped with N and S atoms have been firstly fabricated. The characterization results show that CDs are successfully synthesized with two separate fluorescence emissions at 468 nm and 628 nm, respectively. The strong and selective interaction of Cr (VI) ions with CDs lead to obvious fluorescence decrease of CDs at 468 nm, which is caused by a mixed quenching mechanism. At the same time, the fluorescence at 628 nm increase. Interestingly, the CDs solution show obvious color change under the daylight and UV light, so visualization detection of Cr (VI) can be realized in water samples. Based on the data of the emission intensity ratios of F468/F628, Cr (VI) can be detected from 3.8 to 38.9 µM combined with the linear correlation coefficient of 0.998, and the lowest detection concentration is 47.2 nM. The platform is satisfactorily applied to the detection of Cr (VI) ions in water samples. In addition, the CDs could be applied as fluorescent probes for cell imaging with dual fluorescent emission.

Propofol suppressed cell proliferation and enhanced apoptosis of bladder cancer cells by regulating the miR-340/CDK2 signal axis.

BACKGROUND: As widely reported, propofol can effectively inhibit tumors development. However, little is known about the molecular mechanisms. Here, we proved that propofol regulated miR-340/CDK2 axis to suppress bladder cancer progression in vitro. METHODS: MicroRNA (MiR)-340 expression in 5637 cells was examined using qRT-PCR. Cyclin-dependent kinase2 (CDK2) expression was detected using both qRT-PCR and western blot. The levels of apoptosis-related proteins and cell cycle-related proteins were evaluated using western blot. CCK-8 assay and BrdU assay were conducted to evaluate cell proliferation. Moreover, flow cytometry assay was employed to assess cell cycle and cell apoptosis. Finally, dual luciferase reporter assay was employed to verify the binding relationship between miR-340 and CDK2. RESULTS: Here we showed that propofol treatment inhibited cell proliferation of 5637 cells but enhanced cell apoptosis. Propofol upregulated miR-340 in a dose and time dependent manner. MiR-340 inhibitor could reverse the effect of propofol on the proliferation and apoptosis of 5637 cells. Next, dual luciferase reporter assay displayed that miR-340 directly bound to the 3'-UTR of CDK2. Finally, inhibition of CDK2 could partly reversed the effect of miR-340 inhibitor on cell proliferation and cell apoptosis of propofol-treated 5637 cells. CONCLUSION: In total, our results proved that targeting miR340/CDK2 axis was novel to enhance the anti-tumor effects of propofol in bladder cancer in vitro, and our study provided alternative therapeutic strategies for clinical treatment of bladder cancer.

Synthesis of carbon dots for Al3+ sensing in water by fluorescence assay.

Fifty-four Eucommia ulmoides leaves were subjected to a hydrothermal technique to synthesize carbon dots (CDs) of 3.55 ± 1.45 nm size. The nanomaterial possessed excellent stability and strong fluorescence emission (φf 42.3%). In a neutral buffer solution, the fluorescence signals of CDs solution were enhanced by aluminium ion without interference from other ions. Degree of enhancement correlated linearly with the Al3+ content in the range 0.01-2.5 mM. Response of this method was fast and sensitive (detection limit was 23 nM). The CDs performed successfully as a sensitive sensor for trace Al3+ determination in water samples, and satisfactory results were obtained.

Role of Metallothionein-1 and Metallothionein-2 in the Neuroprotective Mechanism of Sevoflurane Preconditioning in Mice.

This study investigated the protective effects and mechanisms of sevoflurane preconditioning (SPC) on neurons in ischemic mice. After SPC, mice were subjected to middle cerebral artery occlusion (MCAO). Cerebral infarction area, cell apoptosis, and metallothionein-1 (MT-1) and metallothionein-2 (MT-2) expressions in MCAO mice were analyzed. Mouse primary neurons were isolated and cultured to determine the location of metallothioneins (MTs) using immunofluorescence. Neurons transfected with MT-siRNA, exogenous MTs, or sh-MTF-1 were subjected to SPC and/or oxygen-glucose deprivation (OGD), and MT-1/MT-2 expression and neurotoxin release were assayed. Meanwhile, neurons were treated with the nitric oxide donor SNAP, degraded SNAP, or the peroxide initiator paraquat, and alterations in MT-1/MT-2 expression and neurotoxicity release were observed. SPC attenuated neuronal injury and apoptosis in MCAO mice. SPC could protect neurons against OGD injury and resulted in upregulated MT-1/MT-2 expression. MT-siRNA transfection led to the downregulated expression of MT-1/MT-2 and increased neurotoxicity, and the expression patterns of these neurons were different from those of neurons transfected with exogenous MTs. The knockdown of MTs could hinder the protective effect of SPC against OGD. Pretreatment with SNAP or paraquat could increase MTF-1 expression in the nucleus of neurons, protecting against OGD injury. The inhibition of nitric oxide and peroxide inhibited the protective role of SPC in OGD by downregulating MTF-1 expression. sh-MTF-1 transfection downregulated MT-1/MT-2 expression and enhanced neurotoxicity in neurons. SPC confers neuroprotection in focal cerebral ischemia mouse models by upregulating the expression of MT-1 and MT-2 by activating NO and peroxide and increasing MTF-1 expression in the nucleus.

Alleviation of sepsis-associated encephalopathy by ginsenoside via inhibition of oxidative stress and cell apoptosis: An experimental study.

Ginsenoside (Rg1) has biological effects including anti-oxidation, anti-inflammation, neuroprotection and neural function improvement, but with few studies in sepsis-associated encephalopathy (SAE). This study thus evaluated Ginsenoside in alleviating SAE, suppressing oxidative stress (OS) or neuronal apoptosis. SAE mouse model was generated and were assigned into SAE, SAE + LD-Rg1, and SAE + HD-Rg1 groups to measure neural apoptosis by flow cytometry. Contents of malondialdehyde (MDA), superoxide dismutase (SOD), GSH-Px and caspase-3 were quantified, and mouse neural reflex function was evaluated. Expression of Nrf2, HO-1 was measured. Mouse neuron MN-c and microglia BV2 were co-cultured in control, LPS, LPS+Rg1 (20µM) and LPS+Rg1 (40µM) groups. Iba-1 expression of BV2 cells was measured by flow cytometry. Contents of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 were quantified. Apoptosis of MN-c cells was measured by flow cytometry, and reactive oxygen species (ROS) content was measured by DCFH-DA staining. SAE mice had elevated caspase-3 activity, cell apoptosis, MDA content, and decreased SOD, GSH-Px activity or neural reflex score comparing to Sham group. Rg1 treatment suppressed caspase-3 activity, apoptotic rate or MDA content, recovered SOD activity, neural reflex score, and expression of Nrf2 and HO-1. LPS treatment elevated Iba-1 expression and release of inflammatory cytokines TNF-α, IL-1ß and IL-6, induced MN-c apoptosis or ROS production, and enhanced Nrf2 and HO-1 expression. Rg1 treatment remarkably inhibited LPS-induced response or cell apoptosis. Ginsenoside can alleviate SAE damage via up-regulating Nrf2 and HO-1 to enhance anti-OS potency and to reduce neural cell apoptosis.

[Application of stroke volume variation-guided liquid therapy in laparoscopic precision hepatectomy].

OBJECTIVE: To observe the safety and impact on the short-term prognosis for patients of stroke volume variation (SVV) goal-directed fluid therapy (GDFT) in laparoscopic precision hepatectomy.
 Methods: A total of 120 patients (18-65 years old) undergoing laparoscopic precision hepatectomy were randomly divided into the fluid therapy group (group S) guided by SVV and the fluid therapy group (group C) guided by central venous pressure group (CVP), with 60 cases in each group. Mean arterial pressure (MAP) and heart rate (HR) were recorded at the following time: at home calm (T0), the operation started (T1), began to cut the liver (T2), the hepatectomy was acheived (T3), and in the end (T4). The lactic acid was measured at T0 to T4 and 1 day after surgery (T5). The amount of blood loss, urine output and fluid supplement, the incidence of intraoperative hypotension, and the use of neophryn were recorded. The recovery of liver function, Hb, and so on were also recorded.
 Results: Compared with the group C, the number of hypotension cases, the amount of blood loss and the amount of neophryn in the group S were decreased during the operation (P<0.05), while the lactic acid values in the group S were not significantly increased than those in the group C at T3 and T4 (P<0.05) and the elevation of AST, ALT, DBIL and TBIL in the group S was significantly decreased than those in the group C at 1 and 2 d after the operation (P<0.05). Hb and Hct in the group S were higher than those in the group C at 1 d after the surgery (P<0.05). Compared with the group C, the postoperative exhaust time and hospitalization time were shortened in the group S (P<0.05), and the infection rate and ICU admission rate were decreased in the group S (P<0.05).
 Conclusion: SVV-guided GDFT in laparoscopic precise hepatectomy is safe and effective. It reduces intraoperative blood loss and benefits the short-term prognosis of patients after operations. High SVV value (13%-17%) is adopted at the liver resection stage, and SVV value with 8%-12% at the end of trans-section may be used as one of intraoperative liquid therapy in laparoscopic precise hepatectomy.