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This study integrates hollow microneedle arrays (HMNA) with a novel jellyfish-shaped electrochemical sensor for the detection of key biomarkers, including uric acid (UA), glucose, and pH, in artificial interstitial fluid. The jellyfish-shaped sensor displayed linear responses in detecting UA and glucose via differential pulse voltammetry (DPV) and chronoamperometry, respectively. Notably, the open circuit potential (OCP) of the system showed a linear variation with pH changes, validating its pH-sensing capability. The sensor system demonstrates exceptional electrochemical responsiveness within the physiological concentration ranges of these biomarkers in simulated epidermis sensing applications. The detection linear ranges of UA, glucose, and pH were 0~0.8 mM, 0~7 mM, and 4.0~8.0, respectively. These findings highlight the potential of the HMNA-integrated jellyfish-shaped sensors in real-world epidermal applications for comprehensive disease diagnosis and health monitoring.
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Biomarcadores , Técnicas Biossensoriais , Técnicas Eletroquímicas , Líquido Extracelular , Agulhas , Líquido Extracelular/química , Biomarcadores/análise , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Concentração de Íons de Hidrogênio , Glucose/análise , Ácido Úrico/análise , Animais , HumanosRESUMO
Helicobacter pylori are transmissible from person to person and among family members. Mother-to-child transmission is the main intrafamilial route of H. pylori transmission. However, how it transmits from mother to child is still being determined. Vaginal yeast often transmits to neonates during delivery. Therefore, H. pylori hosted in yeast might follow the same transmission route. This study aimed to detect intracellular H. pylori in vaginal and fecal yeasts isolates and explore the role of yeast in H. pylori transmission. Yeast was isolated from the mothers' vaginal discharge and neonates' feces and identified by internal transcribed spacer (ITS) sequencing. H. pylori 16S rRNA and antigen were detected in yeast isolates by polymerase chain reaction and direct immunofluorescence assay. Genetic relationships of Candida strains isolated from seven mothers and their corresponding neonates were determined by random amplified polymorphic DNA (RAPD) fingerprinting and ITS alignment. The Candida isolates from four mother-neonate pairs had identical RAPD patterns and highly homologous ITS sequences. The current study showed H. pylori could be sheltered within yeast colonizing the vagina, and fecal yeast from neonates is genetically related to the vaginal yeast from their mothers. Thus, vaginal yeast presents a potential reservoir of H. pylori and plays a vital role in the transmission from mother to neonate.
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Infecções por Helicobacter , Helicobacter pylori , Recém-Nascido , Humanos , Feminino , Mães , Helicobacter pylori/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Transmissão Vertical de Doenças Infecciosas , Saccharomyces cerevisiae/genética , RNA Ribossômico 16S/genética , Infecções por Helicobacter/diagnóstico , Candida/genética , FezesRESUMO
The 2LiF-BeF2 (FLiBe) salt melt is considered the primary choice for a coolant and fuel carrier for the generation IV molten salt reactor (MSR). However, the basics of ionic coordination and short-range ordered structures have been rarely reported due to the toxicity and volatility of beryllium fluorides, as well as the lack of suitable high-temperature in situ probe methods. In this work, the local structure of FLiBe melts was investigated in detail using the newly designed HT-NMR method. It was found that the local structure was comprised of a series of tetrahedral coordinated ionic clusters (e.g., BeF42-, Be2F73-, Be3F104-, and polymeric intermediate-range units). Li+ ions were coordinated by BeF42- ions and the polymeric Be-F network through the analysis of the NMR chemical shifts. Using solid-state NMR, the structure of solid FLiBe solidified mixed salts was confirmed to form a 3D network structure, significantly similar to those of silicates. The above results provide new insights into the local structure of FLiBe salts, which verifies the strong covalent interactions of Be-F coordination and the specific structural transformation to the polymeric ions above 25% BeF2 concentration.
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BACKGROUND: Montmorillonite (Mt) and its derivatives are now widely used in industrial and biomedical fields. Therefore, safety assessments of these materials are critical to protect human health after exposure; however, studies on the ocular toxicity of Mt are lacking. In particular, varying physicochemical characteristics of Mt may greatly alter their toxicological potential. To explore the effects of such characteristics on the eyes, five types of Mt were investigated in vitro and in vivo for the first time, and their underlying mechanisms studied. RESULTS: The different types of Mt caused cytotoxicity in human HCEC-B4G12 corneal cells based on analyses of ATP content, lactate dehydrogenase (LDH) leakage, cell morphology, and the distribution of Mt in cells. Among the five Mt types, Na-Mt exhibited the highest cytotoxicity. Notably, Na-Mt and chitosan-modified acidic Na-Mt (C-H-Na-Mt) induced ocular toxicity in vivo, as demonstrated by increases corneal injury area and the number of apoptotic cells. Na-Mt and C-H-Na-Mt also induced reactive oxygen species (ROS) generation in vitro and in vivo, as indicated by 2',7'-dichlorofluorescin diacetate and dihydroethidium staining. In addition, Na-Mt activated the mitogen-activated protein kinase signaling pathway. The pretreatment of HCEC-B4G12 cells with N-acetylcysteine, an ROS scavenger, attenuated the Na-Mt-induced cytotoxicity and suppressed p38 activation, while inhibiting p38 activation with a p38-specific inhibitor decreased Na-Mt-induced cytotoxicity. CONCLUSIONS: The results indicate that Mt induces corneal toxicity in vitro and in vivo. The physicochemical properties of Mt greatly affect its toxicological potential. Furthermore, ROS generation and p38 activation contribute at least in part to Na-Mt-induced toxicity.
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Bentonita , Neuropatia Óptica Tóxica , Humanos , Espécies Reativas de Oxigênio/metabolismo , Bentonita/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/farmacologia , ApoptoseRESUMO
POLAR-2 is a space-borne polarimeter, built to investigate the polarization of Gamma-Ray Bursts and help elucidate their mechanisms. The instrument is targeted for launch in 2024 or 2025 aboard the China Space Station and is being developed by a collaboration between institutes from Switzerland, Germany, Poland and China. The instrument will orbit at altitudes between 340km and 450km with an inclination of 42 ∘ and will be subjected to background radiation from cosmic rays and solar events. It is therefore pertinent to better understand the performance of sensitive devices under space-like conditions. In this paper we focus on the radiation damage of the silicon photomultiplier arrays S13361-6075NE-04 and S14161-6050HS-04 from Hamamatsu. The S13361 are irradiated with 58MeV protons at several doses up to 4.96Gy, whereas the newer series S14161 are irradiated at doses of 0.254Gy and 2.31Gy. Their respective performance degradation due to radiation damage are discussed. The equivalent exposure time in space for silicon photomultipliers inside POLAR-2 with a dose of 4.96Gy is 62.9years (or 1.78years when disregarding the shielding from the instrument). Primary characteristics of the I-V curves are an increase in the dark current and dark counts, mostly through cross-talk events. Annealing processes at 25 ∘ C were observed but not studied in further detail. Biasing channels while being irradiated have not resulted in any significant impact. Activation analyses showed a dominant contribution of ß + particles around 511 keV. These resulted primarily from copper and carbon, mostly with decay times shorter than the orbital period.
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A CuI-TbIII heterometallic MOF, namely 1·DMF, was obtained via a coordination assembly process of isonicotinic acid with CuI and TbIII. 1·DMF can be switched to 1·MeOH in methanol with a luminescent emission response. Meanwhile, 1·MeOH exhibits a reversible single-crystal transformation to 1·DMF after immersion in DMF. Both MOFs have superior physicochemical stability. The 1·DMF-based biosensor has a remarkable sensing performance toward penicillin.
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Cobre/química , Luminescência , Compostos Organometálicos/química , Penicilinas/análise , Térbio/química , Teoria da Densidade Funcional , Modelos Moleculares , Conformação Molecular , Penicilinas/químicaRESUMO
AIM: miR-155 is a pro-inflammatory or anti-inflammatory factor depending on the cell type in which it is expressed. miR-155 controls apoptosis and matrix degradation in nucleus pulposus (NP) cells in vitro. The aim of this study is to explore the effect of miR-155 in vivo and further investigate the mechanism of miR-155 in vitro. METHODS: MRI, hematoxylin-eosin staining, or Collagen-II immunochemistry were performed to observe intervertebral disk degeneration in conditional miR-155 overexpression mice and miR-155 knockout mice. In vitro, a dual luciferase reporter assay, real-time PCR and western blot experiments were performed to demonstrate the effect of miR-155 on the expression of catabolic genes induced by inflammatory cytokines and determine the role of ß-catenin and C/EBPß in the miR-155-mediated modulation of the expression of catabolic genes. RESULTS: Degeneration was observed in the lumbar disks of 1-year-old miR-155 knockout mice but not in the conditional miR-155 overexpression mice. miR-155 overexpression repressed the catabolic effect induced by TNF-α or IL-1ß in vitro. Furthermore, specifically in NP cells, miR-155 overexpression suppressed the expression of C/EBPß but not of ß-catenin. Additionally, in the loss-of-function experiments using C/EBPß siRNA, C/EBPß knockdown repressed the expression of catabolic genes induced by TNF-α and IL-1ß, which is consistent with the miR-155 results. CONCLUSION: miR-155 is a sustainable factor for intervertebral disk and suppresses the expression of catabolic genes induced by TNF-α and IL-1ß by targeting C/EBPß in rat NP cells.
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Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Interleucina-1beta/farmacologia , MicroRNAs/metabolismo , Núcleo Pulposo/citologia , Fator de Necrose Tumoral alfa/farmacologia , Animais , Sequência de Bases , Regulação da Expressão Gênica/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Degeneração do Disco Intervertebral/patologia , Camundongos Knockout , Camundongos Transgênicos , MicroRNAs/genética , Modelos Biológicos , Ratos Sprague-Dawley , beta Catenina/metabolismoRESUMO
AIM: The objective of this study is to explore the effect of inflammatory cytokines on a disintegrins and metalloproteinase with thrombospondin motifs 7 (ADAMTS7) and to demonstrate the role of Sp1, AP-1 and NF-κB signaling on the ADAMTS7 regulation during inflammation in NP cells. METHODS: Real-time PCR was to detect the effect of ADAMTS7 knockdown on the expression of catabolic enzymes during inflammatory condition in NP cells. Real-time PCR, western blot, immunofluorescence and transfection experiments were used to observe the effect of tumor necrosis factor-α (TNF-α) or interleukin-1ß on the expression and the activity of ADAMTS7, and demonstrated the role to Sp1, AP-1 and NF-κB in the regulation of ADAMTS7 during inflammation. RESULTS: As other cells, ADAMTS7 knockdown suppressed the mRNA expression of catabolic factors during inflammation in human NP cells. However, the expression of ADAMTS7 mRNA and protein and the activity of ADAMTS7 promoter were refractory to inflammatory cytokines. In addition, Sp1, AP-1, not NF-κB signaling sustained the expression of ADAMTS7 mRNA, protein, as well as promoter activity during inflammation in NP cells. CONCLUSION: ADAMTS7 played a crucial role in the expression of catabolic genes in the presence of TNF-α and AP-1, Sp1, not NF-κB signaling were critical for the maintenance of ADAMTS7 expression during inflammation in NP cells.
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Inflamação/metabolismo , Núcleo Pulposo/citologia , Fator de Transcrição AP-1/metabolismo , Proteína ADAMTS7/genética , Proteína ADAMTS7/metabolismo , Abietanos/farmacologia , Animais , Benzamidas/farmacologia , Células HEK293 , Humanos , Inflamação/genética , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Ratos , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Tiazóis/farmacologia , Fator de Transcrição AP-1/antagonistas & inibidoresRESUMO
Developing rechargeable Na-CO2 batteries is significant for energy conversion and utilization of CO2 . However, the reported batteries in pure CO2 atmosphere are non-rechargeable with limited discharge capacity of 200â mAh g(-1) . Herein, we realized the rechargeability of a Na-CO2 battery, with the proposed and demonstrated reversible reaction of 3 CO2 +4 Naâ2 Na2 CO3 +C. The battery consists of a Na anode, an ether-based electrolyte, and a designed cathode with electrolyte-treated multi-wall carbon nanotubes, and shows reversible capacity of 60000â mAh g(-1) at 1â A g(-1) (≈1000â Wh kg(-1) ) and runs for 200â cycles with controlled capacity of 2000â mAh g(-1) at charge voltage <3.7â V. The porous structure, high electro-conductivity, and good wettability of electrolyte to cathode lead to reduced electrochemical polarization of the battery and further result in high performance. Our work provides an alternative approach towards clean recycling and utilization of CO2 .
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The following are our views regarding the "letter to the editor" (Helicobacter is preserved in yeast vacuoles! Does Koch's postulates confirm it?) by Alipour and Gaeini, and the response "letter to the editor" (Candida accommodates non-culturable Helicobacter pylori in its vacuole-Koch's postulates aren't applicable) by Siavoshi and Saniee. Alipour and Gaeini rejected the methods, results, discussion, and conclusions summarized in a review article by Siavoshi and Saniee. The present article reviews and discusses evidence on the evolutionary adaptation of Helicobacter pylori (H. pylori) to thrive in Candida cell vacuoles and concludes that Candida could act as a Trojan horse, transporting potentially infectious H. pylori into the stomach of humans.
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Infecções por Helicobacter , Helicobacter pylori , Helicobacter pylori/patogenicidade , Humanos , Infecções por Helicobacter/microbiologia , Candida/fisiologia , Candida/crescimento & desenvolvimento , Candida/patogenicidade , Vacúolos/microbiologia , Vacúolos/metabolismo , Estômago/microbiologia , Mucosa Gástrica/microbiologiaRESUMO
Different techniques have been described for glenoid fractures, there is still a need for safe and effective agents to promote outcomes. From January 2016 to April 2021, the clinical data of 17 patients with pulley type IA fractures treated by the V-shaped fixation technique under shoulder arthroscopy were retrospectively analyzed. Preoperative X-ray, CT, and MRI examinations were completed. The functional score of the shoulder joint, such as the visual analog scale (VAS), Constant score, and Modified Rowe score, was used to evaluate the preoperative and final follow-up clinical outcomes. The active shoulder range of motion (ROM) was also collected preoperatively and at the final postoperative follow-up. Accordingly, intraoperative and postoperative complications were also observed. The mean follow-up was 49.52 months (16-79 months). The patients' follow-up exams showed that shoulder joint flexion, abduction, external rotation, internal rotation, and pain were not significantly different from those of the contralateral side (p > .05). The mean Constant score was 83.52 (58-98), and the average Modified Rowe score was 94.29 (70-100). X-ray and CT films of all cases showed good healing without articular depression or steps. Three patients had traumatic arthritis, with VAS <3 pain. No postoperative complications, such as infections, nerve or vessel damage, or suture anchor problems occurred during the follow-up period. Using the Double-pull, V-shaped fixation technique can stabilize the reduction of glenoid fractures while reducing the possibility of bone destruction. It is a good solution and provides an opportunity to treat rotator cuff tears associated with the procedure.
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Artroscopia , Fixação Interna de Fraturas , Humanos , Masculino , Artroscopia/métodos , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Fixação Interna de Fraturas/métodos , Amplitude de Movimento Articular , Cavidade Glenoide/cirurgia , Cavidade Glenoide/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Fraturas Ósseas/diagnóstico por imagemRESUMO
Background: This study aimed to evaluate the reference value of the femoral anterior tangent (FAT) line as a guidance of distal femoral rotation on magnetic resonance images (MRI). Methods: We retrospectively included 81 patients (106 knees) diagnosed as ailing from primary knee osteoarthritis. The indirect rotational axes including the FAT line, the perpendicular line to the anteroposterior axis (pAPA), and the posterior condylar axis (PCA) were identified on MRI, and their angles related to the clinical transepicondylar axis (cTEA) or surgical transepicondylar axis (sTEA) were measured. The patients were further divided into subgroups according to the Kellgren-Lawrence (K-L) grades, the joint-line convergence angle (JLCA), and the arithmetic hip-knee-ankle angle (aHKA) to assess the variance of different rotational reference axes. Results: The FAT line was -11.8° ± 3.6° internally rotated to the cTEA and -7.5° ± 3.6° internally rotated to the sTEA. The FAT/cTEA angle and the FAT/sTEA angle shared a similar frequency distribution pattern but a little greater variance to the pAPA/cTEA angle and the PCA/cTEA angle. The PCA/cTEA angle in the JLCA |x| ≥ 6° subgroup was significantly smaller than in the two other JLCA subgroups. The pAPA/cTEA angle and the PCA/cTEA angle also presented statistical significance within the aHKA subgroups. While the FAT/cTEA angle and the FAT/sTEA angle demonstrated superior stability among the different K-L grades, JLCA subgroups, and aHKA subgroups. Conclusion: The FAT line was less affected by the degree of knee osteoarthritis and lower limb alignment, which could serve as a reliable alternative reference axis for the distal femoral rotational alignment in total knee arthroplasty.
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Garnet-type solid-state Li metal batteries (SSLMBs) are viewed as hopeful next-generation batteries due to their high energy density and safety. However, the major obstacle to the development of garnet-type SSLMBs is the lithiophobicity of Li6.75La3Zr1.75Ta0.25O12 (LLZTO), resulting in a large interfacial impedance. Herein, a LiI/ZnLix mixed ion/electron conductive buffer layer is constructed at the interface by an in situ reaction of molten Li metal with ZnI2 film. This mixed buffer layer ensures close contact between the Li metal and garnet, significantly reducing interfacial impedance. As a result, the Li symmetrical cell with the LiI/ZnLix buffer layer shows an interface impedance of 10.3 Ω cm2, much lower than that of the cell with bare LLZTO (1173.4 Ω cm2). The critical current density (CCD) is up to 2.3 mA cm-2, and the symmetric cells present a long cycle life of 2000 h at 0.1 mA cm-2 and 800 h at 1.0 mA cm-2. In addition, the full cells assembled with the LiFePO4 cathode show a capacity of 143.9 mA h g-1 after 200 cycles at 0.5C with a low-capacity decay of 0.021% per cycle. This work reveals a simple, feasible, and practical interface modification strategy for solid-state Li metal batteries.
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Molten NaF-BeF2 salt is widely considered a promising candidate to replace FLiBe in molten salt reactor applications, which is crucial to reducing the operating costs of the molten salt reactor. Studies on beryllium compounds are rarely conducted due to their volatility and high toxicity. Herein, the Be-F coordination structure of NaF/BeF2 mixed salts was investigated in-depth through various HT-NMR and solid-state NMR methods, which are optimized to be appropriate for the detection of beryllium compounds. It was found that Na2BeF4 and NaBeF3 crystals were transformed into amorphous tetrahedral coordinated networks when there was an increase in the BeF2 concentration in the mixed salts. The main coordinate structure comparisons between FNaBe and FLiBe were analyzed, which exhibit high similarity due to the covalent effect of Be-F bonding, demonstrating the theoretical feasibility of applying FNaBe salts as a substitute for FLiBe in MSR systems. In addition, the transition from the crystal phase to the amorphous phase occurred at a lower BeF2 concentration for FNaBe than that for FLiBe. This was further verified by the results of ab initio molecular dynamics (AIMD) simulation that FNaBe melts had more disordered structures, thus causing slight changes in their physical properties.
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OBJECTIVES: This study aimed to analyse and determine the role of aortic length and curvature in the pathogenesis of acute type A aortic dissection (ATAAD) with ascending aortic diameters (AADs) <5 cm. METHODS: We reviewed the clinical and imaging data of patients with ATAAD (n = 201) and ascending aortic dilation (n = 83). Thoracic aortic bending index (TABI) was used to quantify aortic curvature and analyse its role in ATAAD below the diameter risk threshold. RESULTS: The AAD was <5.0 and <4.0 cm in 78% and 37% of patients with ATAAD, respectively. The median ascending aortic length (AAL) was 104.6 mm (Q1-Q3, 96.5-113.6 mm), and in 62.7% of patients, it was <11 cm. The median TABI was 14.99 mm/cm (Q1-Q3, 14.18-15.86 mm/cm). Patients with ATAAD and those with aortic dilation were matched for AAD, age, sex, height and other clinical factors. After matched, the dissection group had higher AALs (median, 102.9 mm; Q1-Q3, 96.0-112.5 mm vs median, 88.2 mm; Q1-Q3, 83.7-95.9 mm; P < 0.001) and TABI (median, 14.84 mm/cm; Q1-Q3, 14.06-15.83 mm/cm vs median, 13.55 mm/cm; Q1-Q3, 13.03-14.28 mm/cm; P < 0.001). According to the regression analysis, the area under the curve required to distinguish patients with ATAAD from those with aortic dilation was 0.831 in AAL, 0.837 in TABI and 0.907 when AAL was combined with TABI. CONCLUSIONS: The patients with ATAAD had higher AAL and TABI than those with aortic dilation. The combination of TABI and AAL might be a potential morphological marker for determining ATAAD risk below the current aortic diameter risk threshold.
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Aneurisma da Aorta Torácica , Dissecção Aórtica , Humanos , Estudos Retrospectivos , Dissecção Aórtica/diagnóstico por imagem , Aorta/cirurgia , Aorta Torácica/diagnóstico por imagem , Tórax , Aneurisma da Aorta Torácica/patologiaRESUMO
Sodium-ion batteries (SIBs) offer several benefits, including cost-efficiency and fast-charging characteristics, positioning them as attractive substitutes for lithium-ion batteries in energy storage applications. However, the inferior capacity and cycling stability of electrodes in SIBs necessitate further enhancement due to sluggish reaction kinetics. In this respect, the utilization of heterostructures, which can provide an inherent electric field and abundant active sites on the surface, has emerged as a promising strategy for augmenting the cycling stability and rate features of the electrodes. This work delves into the utilization of V1.13Se2/V2O3 heterostructure materials as anodes, initially fabricated via a simplified one-step solid-state sintering technique. The high pseudocapacitance and low characteristic relaxation time constant give the V1.13Se2/V2O3 heterostructure impressive properties, such as a high capacity of 328.5 mAh g-1 even after 1500 cycles at a high current density of 2 A g-1 and rate capability of 278.9 mAh g-1 at 5 A g-1. Moreover, the assembled sodium-ion full battery delivers a capacity of 118.5 mAh g-1 after 1000 cycles at 1 A g-1. These findings provide novel insight and guidance for the rapid synthesis of heterojunction materials and the advancement of SIBs.
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BACKGROUND: Helicobacter pylori infections are generally acquired during childhood and affect half of the global population, but its transmission route remains unclear. It is reported that H. pylori can be internalized into Candida, but more evidence is needed for the internalization of H. pylori in human gastrointestinal Candida and vaginal Candida. METHODS: Candida was isolated from vaginal discharge and gastric mucosa biopsies. We PCR-amplified and sequenced H. pylori-specific genes from Candida genomic DNA. Using optical and immunofluorescence microscopy, we identified and observed bacteria-like bodies (BLBs) in Candida isolates and subcultures. Intracellular H. pylori antigen were detected by immunofluorescence using Fluorescein isothiocyanate (FITC)-labeled anti-H. pylori IgG antibodies. Urease activity in H. pylori internalized by Candida was detected by inoculating with urea-based Sabouraud dextrose agar, which changed the agar color from yellow to pink, indicating urease activity. RESULTS: A total of 59 vaginal Candida and two gastric Candida strains were isolated from vaginal discharge and gastric mucosa. Twenty-three isolates were positive for H. pylori 16S rDNA, 12 were positive for cagA and 21 were positive for ureA. The BLBs could be observed in Candida cells, which were positive for H. pylori 16S rDNA, and were viable determined by the LIVE/DEAD BacLight Bacterial Viability kit. Fluorescein isothiocyanate (FITC)-conjugated antibodies could be reacted specifically with H. pylori antigen inside Candida cells by immunofluorescence. Finally, H. pylori-positive Candida remained positive for H. pylori 16S rDNA even after ten subcultures. Urease activity of H. pylori internalized by Candida was positive. CONCLUSION: In the form of BLBs, H. pylori can internalize into gastric Candida and even vaginal Candida, which might have great significance in its transmission and pathogenicity.
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Candidíase Vulvovaginal , Infecções por Helicobacter , Helicobacter pylori , Descarga Vaginal , Feminino , Humanos , Urease/genética , Infecções por Helicobacter/microbiologia , Fluoresceína-5-Isotiocianato , Ágar , Antígenos de Bactérias/genética , Mucosa Gástrica/microbiologia , Candida/genética , Biópsia , DNA Ribossômico , Ureia , Proteínas de Bactérias/genéticaRESUMO
Zinc-ion batteries (ZIBs) are rapidly emerging as safe, cost-effective, nontoxic, and environmentally friendly energy storage systems. However, mildly acidic electrolytes with depleted protons cannot satisfy the huge demand for proton reactions in MnO2 electrodes and also cause several issues in ZIBs, such as rapidly decaying cycling stability and low reaction kinetics. Herein, we propose a pH-buffering strategy in which KH2PO4 is added to the electrolyte to overcome the problems caused by low proton concentrations. This strategy significantly improves the rate and cycle stability performance of zinc-manganese batteries, delivering a high capacity of 122.5 mAh/g at a high current density of 5 A/g and enabling 9000 cycles at this current density, with a remaining capacity of 70 mAh/g. Ex-situ X-ray diffraction and scanning electron microscopy analyses confirmed the generation/dissolution of Zn3PO4·4H2O and Zn4(OH)6(SO4)·5H2O, byproducts of buffer products and proton reactions. In-situ pH measurements and chemical titration revealed that the pH change during the electrochemical process can be adjusted to a low range of 2.2-2.8, and the phosphate distribution varies with the pH range. Those results reveal that H2PO4- provides protons to the cathode through the chemical balance of HPO42-, HPO42-, and Zn3PO4·4H2O. This study serves as a guide for studying the influences and mechanisms of buffering additives in Zn-MnO2 batteries.
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A facile anion-exchange precipitation method was used to synthesize bifunctional Ag/AgBr/Co-Ni-NO(3) layered double hydroxide (LDH) nanocomposites by adding AgNO(3) solution to a suspension of Co-Ni-Br LDH. The Ag/AgBr nanoparticles were highly dispersed on the sheets of Co-Ni-NO(3) LDH. The prepared nanocomposites were used to adsorb and photocatalytically degrade organic pollutants from water. Without light illumination, the nanocomposites quickly adsorbed methyl orange, and the adsorptive capacity, which can reach 230â mg g(-1), is much higher than those of Co-Ni-Br LDH, Ag/AgBr, and activated carbon. The photocatalytic activities of the nanocomposites for the removal of dyes and phenol are higher than those of Co-Ni-Br LDH and Ag/AgBr. The proposed method can be applied to prepare other LDH/silver salt composites. The high absorptive capacity and good photocatalytic activity of such nanostructures could have wide applications in wastewater treatment.
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Cobalto/química , Hidróxidos/química , Nanocompostos/química , Nanopartículas/química , Níquel/química , Compostos de Prata/química , Adsorção , Catálise , Luz , Fotoquímica , Difração de Raios XRESUMO
In this work, the distribution and dynamics of Li+ ions in ß-CD-PEO/Li+ (ß-CD, ß-cyclodextrin; PEO, polyethylene-oxides) crystalline polymer electrolytes were investigated by solid-state NMR to enlighten the ionic conduction mechanism. Specifically, 7Li-6Li REDOR NMR and variable-contact-time 1H-6Li CP/MAS NMR were adopted for the study. The results demonstrate that Li+ ions coordinated by polymer chains have relatively compact spatial density and fast dynamics, which facilitate the improvement of the electrochemical properties. Additionally, the variation of the distribution and dynamics of the Li+ ions and the ionic conduction mechanism were studied and discussed by altering the amount of the Li+ ions. This work deepens our understanding of the distribution and dynamics of Li+ ions in ß-CD-PEO/Li+ crystals and demonstrates possible future applications of solid-state NMR on the study of the polymer electrolytes.