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The expansion of anatomically modern humans (AMHs) from Africa around 65,000 to 45,000 y ago (ca. 65 to 45 ka) led to the establishment of present-day non-African populations. Some paleoanthropologists have argued that fossil discoveries from Huanglong, Zhiren, Luna, and Fuyan caves in southern China indicate one or more prior dispersals, perhaps as early as ca. 120 ka. We investigated the age of the human remains from three of these localities and two additional early AMH sites (Yangjiapo and Sanyou caves, Hubei) by combining ancient DNA (aDNA) analysis with a multimethod geological dating strategy. Although U-Th dating of capping flowstones suggested they lie within the range ca. 168 to 70 ka, analyses of aDNA and direct AMS 14C dating on human teeth from Fuyan and Yangjiapo caves showed they derive from the Holocene. OSL dating of sediments and AMS 14C analysis of mammal teeth and charcoal also demonstrated major discrepancies from the flowstone ages; the difference between them being an order of magnitude or more at most of these localities. Our work highlights the surprisingly complex depositional history recorded at these subtropical caves which involved one or more episodes of erosion and redeposition or intrusion as recently as the late Holocene. In light of our findings, the first appearance datum for AMHs in southern China should probably lie within the timeframe set by molecular data of ca. 50 to 45 ka.
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Arqueologia , Cavernas/química , DNA Antigo/análise , Fósseis , Sedimentos Geológicos/análise , Migração Humana/história , Datação Radiométrica/métodos , China , História Antiga , HumanosRESUMO
Qubits are the basic unit of quantum information and computation. To realize quantum computing and information processing, the decoherence times of qubits must be long enough. Among the studies of molecule-based electron spin qubits, most of the work focused on the ions with the spin S=1/2, where only single-bit gates can be constructed. However, quantum operations require the qubits to interact with each other, so people gradually carry out relevant research in ions or systems with S>1/2 and multilevel states. In this work, a two-dimensional (2D) oxygen-coordinated GdIII NaI -based oxamato supramolecular coordination framework, Na[Gd(4-HOpa)4 (H2 O)] â 2H2 O (1, 4-HOpa=N-4-hydroxyphenyloxamate), was selected as a possible carrier of qubit. The field-induced slow magnetic relaxation shows this system has phonon bottleneck (PB) effect at low temperatures with a very weak magnetic anisotropy. The pulse electron paramagnetic resonance studies show the spin-lattice and spin-spin relaxation times are T1 =1.66â ms at 4â K and Tm =4.25â µs at 8â K for its diamagnetically diluted sample (1Gd0.12 %). It suggested that the relatively long decoherence time is mainly ascribed to its near isotropic and the PB effect from resonance phonon trapped for pure sample, while the dilution further improves its qubit performance.
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An accurate, easy setup, low-cost, and time-saving method for measuring glucose concentration was proposed. An all-grating-based glucose concentration measurement system contained moving-grating-based heterodyne interferometry and a grating-based self-align sensor. By combining the first-order diffraction lights from two separated moving gratings by a polarization beam splitter and creating S- and P-polarized light interference by an analyzer, the interference signal could be a heterodyne light source with a heterodyne frequency depending on the relative velocities of the two moving gratings. Next, a grating-based self-align sensor was used to make the optical configuration setup easy and accurate. Moreover, the sensor was deposited on GOx film to improve the measurement sensitivity and specificity for glucose. Finally, the phase change induced by the reaction of the sensor and glucose solutions was detected. The validity of this method was proved, and the measurement resolution can reach 2 mg/dL.
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In this study, a hybrid method for high-quality rapid drilling of transparent hard materials which combines femtosecond laser (fs-laser) Bessel beam modifying materials and selective wet etching is presented. Using this method, micro-holes with no taper of different sizes (from 10 to 35 µm) and shapes (square, triangle, circular, and pentagram) are fabricated. Bessel beams of different lengths can be generated flexibly by loading different computer-generated holograms (CGHs) into the spatial light modulator (SLM) and the maximum length of light interacting with materials can reach 320 µm, leading to a reduction of the laser scanning time by two orders of magnitude. Moreover, a set of three-dimensional multi-layer submicron through-holes in crystal materials is also realized, with an aspect ratio of more than 1000 for each hole. These results indicate that this method has broad application potential in chip packaging, aviation manufacturing, single particle catalysis, and other fields.
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Herein, a vector scanning subtractive manufacturing technology is proposed to rapidly fabricate smooth micro-optical components, which is based on the vector scanning method and wet etching. Compared with the raster scanning method, the vector scanning method increases processing efficiency by nearly two orders and mitigates a buildup of stress around the laser processed region, avoiding the generation of cracks. The Letter demonstrates the fabrication of three-dimensional (3D) micro-structures with various sizes and morphologies. For example, micro-concave lenses with diameters of 20 µm to 140 µm, heights of 10 µm to 70 µm, and surface roughness of 29 nm are flexibly fabricated on sapphire by vector scanning subtractive manufacturing technology. The results indicate that the technology has broad prospects in the field of monolithic integrated 3D all-solid-state micro-optics.
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BACKGROUND: Reduced port laparoscopic surgery (RPLS), as a more minimally invasive treatment alternative to conventional laparoscopic surgery (CLS), has been increasing in recent years. 1 With the accumulation of surgical experience and improvements in surgical techniques, the indication of RPLS has been gradually extended from benign diseases to malignant tumors, including gastric cancer. 2-4 However, due to the lack of counteraction and triangulation, lymphadenectomy during reduced port laparoscopic gastrectomy (RPLG) for gastric cancer was considered challenging. In this study, we report our experience performing RPLG with D2 lymphadenectomy for distal gastric cancer. METHODS: A disposable, single-incision, multiport, laparoscopic surgery trocar was used through a 3-cm incision at the umbilicus for the laparoscopist and surgeon's right hand. One 12-mm trocar was inserted at the upper-right quadrant for the surgeon's left hand. Distal gastrectomy with D2 lymphadenectomy was performed in the same manner with CLS. 5 After extracting the resected specimen through the umbilicus incision, intracorporeal Roux-en-Y or B-II gastrojejunostomy was used for reconstruction. RESULTS: RPLG with D2 lymphadenectomy was performed on five patients from April 2017 to June 2017. No intraoperative event requiring conversion to CLS or open surgery occurred. No postoperative complication was observed. The median operating time and blood loss was 166 min and 50 ml. The mean number of retrieved lymph nodes was 32.7. Postoperatively, the mean time to first flatus, soft intake, and hospital stay was 2.6, 3.5, and 6.7 days respectively. CONCLUSIONS: RPLG with D2 lymphadenectomy might be safe and feasible in selected patients.
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Gastrectomia/métodos , Laparoscopia/métodos , Excisão de Linfonodo/métodos , Neoplasias Gástricas/cirurgia , Anastomose em-Y de Roux/métodos , Feminino , Gastroenterostomia/métodos , Humanos , Jejuno/cirurgia , Pessoa de Meia-Idade , Estômago/cirurgiaRESUMO
Due to heterogeneous morphological and immunophenotypic features, approximately 50% of peripheral T-cell lymphomas are unclassifiable and categorized as peripheral T-cell lymphomas, not otherwise specified. These conditions have an aggressive course and poor clinical outcome. Identification of actionable biomarkers is urgently needed to develop better therapeutic strategies. Epigenetic alterations play a crucial role in tumor progression. Histone modifications, particularly methylation and acetylation, are generally involved in chromatin state regulation. Here we screened the core set of genes related to histone methylation (KMT2D, SETD2, KMT2A, KDM6A) and acetylation (EP300, CREBBP) and identified 59 somatic mutations in 45 of 125 (36.0%) patients with peripheral T-cell lymphomas, not otherwise specified. Histone modifier gene mutations were associated with inferior progression-free survival time of the patients, irrespective of chemotherapy regimens, but an increased response to the histone deacetylase inhibitor chidamide. In vitro, chidamide significantly inhibited the growth of EP300-mutated T-lymphoma cells and KMT2D-mutated T-lymphoma cells when combined with the hypomethylating agent decitabine. Mechanistically, decitabine acted synergistically with chidamide to enhance the interaction of KMT2D with transcription factor PU.1, regulated H3K4me-associated signaling pathways, and sensitized T-lymphoma cells to chidamide. In a xenograft KMT2D-mutated T-lymphoma model, dual treatment with chidamide and decitabine significantly retarded tumor growth and induced cell apoptosis through modulation of the KMT2D/H3K4me axis. Our work thus contributes to the understanding of aberrant histone modification in peripheral T-cell lymphomas, not otherwise specified and the stratification of a biological subset that can benefit from epigenetic treatment.
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Proteínas de Ligação a DNA/metabolismo , Genes Modificadores/genética , Histonas/metabolismo , Linfoma de Células T Periférico/tratamento farmacológico , Linfoma de Células T Periférico/genética , Mutação , Proteínas de Neoplasias/metabolismo , Acetilação , Aminopiridinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Benzamidas/farmacologia , Linhagem Celular Tumoral , Análise Mutacional de DNA , Decitabina/farmacologia , Xenoenxertos , Histonas/genética , Humanos , Linfoma de Células T Periférico/mortalidade , Metilação , Camundongos , Prognóstico , Análise de Sobrevida , Células Tumorais CultivadasRESUMO
We report rapid and mask-free fabrication of a sapphire concave microlens array by a combined method of femtosecond laser holographic processing and wet etching. The method features high fabrication efficiency, as crater arrays can be created on sapphire through a parallel processing manner, and the subsequent wet etching facilitates the formation of microlens arrays with a smooth surface. More importantly, the size and spacing of the concave microlenses can be well tuned by varying the distance of craters and etching time. Two types of microlens arrays with a spacing of 25 and 40 µm have been successfully fabricated, both of which showed good imaging performance. This method holds great promise for developing sapphire-based micro-optical components.
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Herein, we report a kinoform phase-type lens (KPL), which is fabricated by femtosecond (fs)-laser-induced refractive index change inside sapphire crystal. By fabricating volume phase gratings in sapphire and measuring the energy ratio of the grating's first and second diffraction orders, the refractive index change in sapphire induced by fs-laser modification was obtained. Then a four-level KPL was designed and fabricated inside sapphire following the experimentally established scaling of the refractive index change and fs-laser power. Importantly, the KPL has unique UV focusing and imaging capability as well as a stable optical performance in different refractive index environments. The KPL embedded in sapphire has the same optical performance after a high-temperature (1050°C) annealing for 30 min. The KPLs in sapphire have great potential to increase light extraction efficiency in GaN blue-UV light-emitting diodes and can be used in micro-optical sensor applications in chemically harsh and high-temperature environments.
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Arsenic (As) and cadmium (Cd) are the most common toxic and harmful heavy metal elements in paddy soils and are easily transferred from the soil to grains. At present, As and Cd and their co-contamination in paddy soils in China are widespread, posing a serious threat to food security and human health. As and Cd have opposite environmental behaviors in soil, and the simultaneous remediation of co-contamination with As and Cd is a current technical difficulty for safe rice production. This review focuses on several practical techniques for simultaneous mitigation of As and Cd uptake and transport in rice in recent years, including water management, passivation, drenching techniques, electrokinetic remediation, phytoremediation, selection of low-accumulation rice varieties, and foliar spraying application. The treatment effects, mechanisms of action, and constraints of various technologies are summarized and analyzed; the development direction of the main barrier control technologies is proposed and the importance of constructing a comprehensive technology model with high regional adaptability is emphasized to provide a reference for the remediation of co-contamination with As and Cd in paddy and safe rice production.
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Arsênio , Oryza , Poluentes do Solo , Humanos , Cádmio/análise , Arsênio/análise , Solo , Poluentes do Solo/análise , TecnologiaRESUMO
Liver cancer is a common malignancy of the digestive system. Hepatocellular carcinoma (HCC) accounts for the most majority of these tumors and it has brought a heavy medical burden to underdeveloped countries and regions. Many factors affect the prognosis of HCC patients, however, there is no specific statistical model to predict the survival time of clinical patients. This study derived a risk factor signature of HCC and reliable clinical prediction model by statistically analyzing The Surveillance, Epidemiology, and End Results (SEER) database patient information using an open source package in the python environment.
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OBJECTIVE: The present study aims to investigate the therapeutic effect and safety of radiofrequency ablation (RFA) of the great saphenous vein in the treatment of varicose veins of the lower extremities. METHODS: Sixty-nine affected limbs of 45 patients were treated with RFA of the great saphenous vein. All patients underwent retrograde puncture of the distal great saphenous vein under the guidance of B-ultrasound. An RFA catheter was introduced 1 cm below the junction of the great saphenous vein and the femoral vein. A tumescent solution was injected around the femoral vein, and the great saphenous vein was ablated section by section from the upper part to the lower part. Twelve months after RFA, color Doppler ultrasound was used to evaluate the closure of great saphenous vein, and changes in the clinical class, etiology, anatomy, pathology (CEAP) classification before and after treatment were compared. The visual analogue score (VAS) was used to evaluate the local pain on the first and third day after operation. The incidence of complications (e.g., phlebitis, thrombosis, infection) was also evaluated. RESULTS: The ablation of the 69 affected limbs in all the 45 patients was successful. Instant B-ultrasound revealed occlusion of the great saphenous vein and the disappearance of blood flow immediately after ablation. There was no reoccurrence in all patients at the 12 month follow-up. The CEAP classification grade after treatment was significantly lower than that before the treatment, and the difference was statistically significant (χ2 = 4.188, P<0.05). The VAS scores on the first and third days after operation were 1.85 ± 0.35 and 0.59 ± 0.21, respectively. Pain was mild, and only two patients required painkillers. No complications were noted, with the exception of five cases of local ecchymosis. CONCLUSION: RFA of the great saphenous vein may represent an effective method for treating varicose veins of the lower extremities. RFA has the advantages of producing less trauma, fewer complications, and a lower incidence of recurrence. KEY WORDS: B-ultrasonography, Pain, Radiofrequency ablation, Varicose veins.
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Ablação por Radiofrequência , Varizes , Insuficiência Venosa , Veia Femoral , Humanos , Extremidade Inferior , Dor/etiologia , Ablação por Radiofrequência/efeitos adversos , Veia Safena/diagnóstico por imagem , Veia Safena/cirurgia , Resultado do Tratamento , Varizes/diagnóstico por imagem , Varizes/etiologia , Varizes/cirurgia , Insuficiência Venosa/cirurgiaRESUMO
Femtosecond laser (fs-laser) is unfavorable in applications for the fabrication of micro-optical devices on hard materials owing to the problems of low fabrication efficiency and high surface roughness. Herein, a hybrid method combining fs-laser scanning, subsequent etching, and annealing was proposed to realize micro-optical devices with low roughness on glass. Compared to traditional laser ablation, the fabrication efficiency in this work was improved by one order of magnitude, and the surface roughness was decreased to 15 nm. Using this method, aspherical convex microlenses and spherical concave microlenses that possess excellent focusing and imaging properties are realized on photosensitive glass. The diameter and height of the microlenses were controlled by adjusting the fabrication parameters. These results indicate that the fs-laser-based hybrid method will open new opportunities for fabricating micro-optical components on hard materials.
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Background and purpose: This study sought to improve methods to identify biomarkers in the neuroendocrine system related to stroke progression to improve the accuracy of traditional tools for evaluating stroke prognosis. Methods: Seventy-four stroke patients and 237 healthy controls were prospectively included. We measured urinary epinephrine (E), noradrenaline (NE), dopamine (DA) and cortisol (F) on days 1, 3, and 5 after stroke onset and plasma F, adrenocorticotropic hormone (ACTH), thyrotropin (TSH), prolactin (PRL), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and growth hormone (GH). The correlation between these hormone levels and 90-day prognosis was analyzed, their value in assessing prognosis was compared with lesion volume and National Institutes of Health Stroke Scale (NIHSS) scores using receiver operating characteristic (ROC) curves, and their correlation with conventional clinical variables was assessed. Results: Levels of F, 24-h urinary free cortisol(UFC), E, NE, DA, and GH on days 1, 3, and 5 were significantly higher in stroke patients than in controls (P < 0.01), while ACTH and TSH decreased, gradually approaching normal within 5 days of onset. Levels of E, NE, F, and 24-h UFC were proportional to severity, and all gradually decreased within 5 days of onset in patients with a good prognosis and gradually increased or remained high in those with a poor prognosis. After adjustment for age, sex, NIHSS, or Glasgow Coma Scale (GCS) score, F > 13.6 µg/dL, ACTH > 22.02 pg/mL and NE > 123.5 µg/ 24 h were identified as risk factors for a poor prognosis 90 days after stroke (P < 0.05). The combination of F, ACTH, NE, white blood cell count (WBC), glucose (Glu), and hemoglobin (Hb) was significantly more accurate than lesion volume (AUC: 0.931 vs. 0.694 P = 0.019) and NIHSS score (AUC: 0.931 vs. 0.746 P = 0.034) in predicting poor prognosis of stroke 1 day after onset. Hormones and traditional clinical variables were correlated to varying degrees, with NE correlating most strongly with 24-h UFC (r = 0.54) and moderately positively with lesion volume (r = 0.40) and NIHSS score (r = 0.45). Conclusions: Stroke causes significant time-phased dynamic changes in the hypothalamic-pituitary-adrenal axis and sympathetic nervous system, and plasma F, ACTH, and urinary NE levels can be used to assess stroke severity and prognosis. Chinese clinical trial registry: Registration Number: ChiCTR1900024992. Registration Date: 2019/8/6.
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OBJECTIVE: To investigate the significance of first determined contents of procalcitonin (PCT), C-reactive protein (CRP), soluble triggering receptor expressed on myeloid cell-1 (sTREM-1) and the clinical pulmonary infection score (CPIS) in the detection of early-onset pneumonia (EOP) developed in patients suffering from stroke. METHODS: From June 2009 to June 2010, 244 stroke patients admitted to the emergency intensive care unit (EICU) in Shanghai Fifth People's Hospital were included in this prospective study. Patients were excluded if they were discharged or died in 24 hours of admission, or pneumonia was diagnosed at the admission. The serum levels of PCT, CRP and sTREM-1 were determined, and the CPIS was calculated in all patients on the day of admission. RESULTS: Among all 244 stroke patients, EOP was diagnosed in 105 of them, and 74 developed severe EOP. The serum levels of PCT, CRP, sTREM-1 and the CPIS in patients with EOP were significantly higher than those in patients who did not develop EOP [PCT (µg/L): 4.20 (0.83,7.75) vs. 0.19 (0.12,0.41); CRP (mg/L): 56.0 (18.5,105.5) vs. 9.0 (7.0,15.0) ; sTREM-1 (ng/L): 56.0 (24.5,111.5) vs. 10.0 (8.0,16.0); CRIS: 4.0 (2.5,4.0) vs. 2.0 (1.0,2.0), all P<0.01], and the levels of PCT, CRP, sTREM-1 and the CPIS in patients with severe EOP were significantly higher than those in patients with mild EOP [PCT (µg/L): 6.10 (3.40,8.83) vs. 0.61 (0.42,1.67); CRP (mg/L): 80.5 (31.5,113.0) vs. 21.0 (12.0,43.0); sTREM-1 (ng/L): 89.0 (53.8,132.8) vs. 21.0 (14.0,43.0); CPIS: 4.0 (3.0,5.0) vs. 2.0 (2.0,3.0), all P<0.01]. The cutoff point, sensitivity and specificity of each indicator to predict EOP were 89.5% and 79.1% in PCT>0.43 µg/L, 78.1% and 78.4% in CRP>16 mg/L, 81.9% and 84.9% in sTREM-1>19 ng/L, 75.2% and 79.9% in CPIS>2. Using PCT>0.43 µg/L combined with CPIS>3 to predict EOP, the sensitivity and specificity reached 81.9% and 92.1% respectively. The cutoff point, sensitivity and specificity of indicators to identify severe EOP were 87.8% and 83.9% in PCT>2.15 µg/L, 70.3% and 77.4% in CRP>43 mg/L, 81.1% and 90.3% in sTREM-1>51 ng/L, 67.6% and 83.9% in CPIS>3. Using PCT>2.15 µg/L combined with sTREM-1>56 ng/L to predict severe EOP, the sensitivity and specificity reached 82.4% and 100.0% respectively. CONCLUSION: The first PCT is an effective indicator to predict EOP. The first CPIS is an index for screening EOP. PCT combined with CPIS may improve the specificity to predict EOP. The first sTREM-1 is a good indicator to identify severe EOP. Combination of first PCT and sTREM-1 may greatly improve the specificity to predict severe EOP.
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Pneumonia/diagnóstico , Acidente Vascular Cerebral/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/metabolismo , Calcitonina/sangue , Peptídeo Relacionado com Gene de Calcitonina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia/sangue , Pneumonia/etiologia , Estudos Prospectivos , Precursores de Proteínas/sangue , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/complicações , Adulto JovemRESUMO
OBJECTIVE: To evaluate the occurrence of severe sepsis and septic shock and the rate of compliance with sepsis bundle in patients with severe sepsis and septic shock in emergency department. METHODS: A prospective study was conducted on consecutive adult patients who were sent to Emergency Department of Ruijin Hospital, Shanghai Jiaotong University School of Medicine by ambulance from May to June in 2009. The occurrence of severe sepsis and septic shock, and the number of the patients in whom who met the criteria of compliance with sepsis bundle were analyzed. RESULTS: Nine hundred and seventeen patients who were sent to the emergency department by ambulance in that period were enrolled in the study. The number of patients with severe sepsis and septic shock was 96. The incidence of severe sepsis and septic shock was 10.47%. Among these patients, the number of patients in whom the sepsis bundle was complied, i.e. sepsis bundle, appropriate cultures were taken before antimicrobial therapy, placement of central venous catheter and monitoring of central venous pressure (CVP) as well as central venous oxygen saturation (ScvO2) within 2 hours, antibiotic therapy within 3 hours, early goal directed therapy (EGDT) within 6 hours, and lactate clearance in 12 hours reached 1.04%, 3.12%, 2.08%, 83.33%, 1.04%, 23.96%. The Results were 1.19%, 3.57%, 2.38%, 83.33%, 1.19%, 26.19% and 0, 0, 0, 83.33%, 0, 8.33% in medical and surgical emergency department respectively. There was no statistical difference between the two divisions (all P>0.05). CONCLUSION: The incidence of severe sepsis and septic shock was high in emergency department, but the rate of recognition of it and the compliance with sepsis bundle were inadequate. It is urgently necessary to enhance the learning and implementation of the guideline.
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Fidelidade a Diretrizes , Sepse/terapia , Choque Séptico/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
UNLABELLED: To develop a hepatitis B virus (HBV) therapeutic vaccine that can induce a broad but specific immune response and significant antitumor effects both in vivo and in vitro, we inserted HBV X protein (HBx)-derived epitopes HBx(52-60), HBx(92-100), and HBx(115-123); a novel subdominant cytolytic T lymphocyte (CTL) epitope HBx(140-148); and the universal T helper epitope pan human leukocyte antigen DR-binding epitope into HBV core protein to form multiepitope peptide-loaded virus-like particles (VLPs). CTL responses against epitope-loaded VLPs were elicited by priming with VLP-pulsed dendritic cells in both HLA-A*0201 transgenic (Tg) mice and peripheral blood lymphocytes from HLA-A2(+)/HBx(+) HBV-infected hepatocellular carcinoma (HCC) patients. The multiepitope peptide-loaded VLPs demonstrated significantly higher immunogenicity in Tg mice than any single responsive epitope. Significant antitumor effects were demonstrated both with primary cultured autologous HCC cells in vitro and tumor-bearing Tg mice in vivo in an HLA-A2-restricted and epitope-specific fashion. CONCLUSION: The significant antitumor effects both in vivo and in vitro demonstrate the potential of multiepitope peptide-loaded VLPs as a vaccine against HCC.
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Carcinoma Hepatocelular/imunologia , Epitopos de Linfócito T , Vacinas contra Hepatite B/biossíntese , Neoplasias Hepáticas/imunologia , Transativadores/imunologia , Proteínas Virais Reguladoras e Acessórias/imunologia , Transferência Adotiva , Animais , Carcinoma Hepatocelular/virologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Células Dendríticas/imunologia , Antígenos HLA-A/metabolismo , Antígeno HLA-A2 , Humanos , Neoplasias Hepáticas/virologia , Camundongos , Camundongos Transgênicos , Estabilidade Proteica , Vacinação , Vacinas de Subunidades Antigênicas/biossínteseRESUMO
Annexin B2 (AnxB2) is a novel member of the annexin family of Ca(2+)- and phospholipid-binding proteins from Cysticercus cellulosae. To obtain highly pure AnxB2 with an easy and inexpensive purification approach, its cDNA was cloned into the prokaryotic expression vector pJLA503 and the translation initiation codon was immediately under the control of the inducible bacteriophage lambda promoters P(R) and P(L). After induction by shifting temperature, large amounts of non-fusion protein were produced in Escherichia coli in a soluble form. Then a novel purification method based on Ca(2+)-dependent phosphatidylserine (PS)-binding activity was established, whereby the purity of AnxB2 was increased to 98.7%. Western blot analysis showed that recombinant AnxB2 was specifically recognized by serum of pigs infected with cysticercosis. In vitro test showed that, the recombinant AnxB2 had anticoagulant activity and platelet binding activity. The expression, purification, and initial characterization of AnxB2 set an important stage for further characterization of the protein.
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Anexinas/genética , Proteínas de Ligação ao Cálcio/genética , Cysticercus/genética , Proteínas de Helminto/genética , Sequência de Aminoácidos , Animais , Anexinas/metabolismo , Bacteriófago lambda , Western Blotting , Proteínas de Ligação ao Cálcio/metabolismo , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Primers do DNA/genética , DNA Complementar/genética , Eletroforese em Gel de Poliacrilamida , Escherichia coli , Vetores Genéticos , Proteínas de Helminto/metabolismo , Dados de Sequência Molecular , Análise de Sequência de ProteínaRESUMO
Polymers are salient participants in the current world, and roughly more than 40%-45% of all industrial polymers were produced by free radical polymerization. Azo-initiators now have been the foremost radical initiator with the virtue of low tendency to undergo chain transfer reactions. Nevertheless, azo-initiators are readily to decompose and release an immense amount of heats and gases under elevated ambient temperature. 2-(1-Cyano-1-methylethyl)azocarboxamide (CABN) was deliberately picked as an example for identifying the hazardous scenarios in the application of azo-initiators. Initially, thermal analysis technologies were used to investigate the thermal decomposition characteristics of CABN, and selected decomposition mechanism functions were verified for the best-fitting thermokinetic model. Subsequently, thermokinetic-based numerical simulations were implemented to evaluate the thermal hazards of CABN under the ideal adiabatic scenario. Process safety parameters under adiabatic conditions including time to maximum rate as well as induction period were consequently retrieved. Furthermore, inherent safety recommendations for free-radical polymerization were established to forestall the process accidents in storage and the applications of azo-initiator.
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Periodic nanostructures have wide applications in micro-optics, bionics, and optoelectronics. Here, a laser interference with subsequent etching technology is proposed to fabricate uniform periodic nanostructures with controllable morphologies and smooth surfaces on hard materials. One-dimensional microgratings with controllable periods (1, 2, and 3 µm) and heights, from dozens to hundreds of nanometers, and high surface smoothness are realized on GaAs by the method. The surface roughness of the periodic microstructures is significantly reduced from 120 nm to 40 nm with a subsequent inductively coupled plasma (ICP) etching. By using laser interference with angle-multiplexed exposures, two-dimensional square- and hexagonal-patterned microstructures are realized on the surface of GaAs. Compared with samples without etching, the diffraction efficiency can be significantly enhanced for samples with dry etching, due to the improvement of surface quality.