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1.
BMC Infect Dis ; 24(1): 382, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589812

RESUMO

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a severe disorder characterized by excessive activation of the immune system, leading to hypercytokinemia and damage to multiple organs. We report a rare case of HLH with myopericarditis caused by Campylobacter infection. CASE PRESENTATION: A 28-year-old male patient with a history of hypertension without medicine control presented at the hospital after a four-day fever, decreasing urine amount, rashes on his trunk and limbs, and other symptoms. He was admitted with a provisional diagnosis of atypical infection and allergic skin rash related to diclofenac. However, his condition deteriorated, and he developed shock, tachycardia, chest distress, and bilateral pleural effusion after admission. Further investigations revealed cardiogenic shock related to myopericarditis, and he was transferred to the ICU. In addition, a stool PCR panel subsequently revealed a positive result for Campylobacter. On day 6, he was diagnosed with HLH. Under Clarithromycin and dexamethasone infusion, leukocytosis, anemia and thrombocytopenia with cardiogenic shock status improved. Then, he was later discharged in stable condition. CONCLUSIONS: HLH and myopericarditis caused by Campylobacter are very rare. Early detection of Campylobacter-induced HLH and multiple organ failure, as well as prompt use of antibiotics and immunosuppressants, can be helpful for prognosis.


Assuntos
Anemia , Campylobacter , Linfo-Histiocitose Hemofagocítica , Miocardite , Trombocitopenia , Masculino , Humanos , Adulto , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/tratamento farmacológico , Linfo-Histiocitose Hemofagocítica/etiologia , Choque Cardiogênico/etiologia , Choque Cardiogênico/complicações , Anemia/complicações , Trombocitopenia/complicações , Miocardite/diagnóstico , Miocardite/complicações
2.
Taiwan J Obstet Gynecol ; 63(1): 68-72, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38216272

RESUMO

OBJECTIVE: This study is aimed to compare the impact on bladder function and symptoms between robotic sacrocolpopexy (RSC) and transvaginal mesh surgery (TVM) in women with pelvic organ prolapse. MATERIALS AND METHODS: This prospective controlled study enrolled patients who received RSC or TVM at our hospital between March 2020 and June 2022. We compared preoperative and postoperative bladder function between two groups by using a questionnaire of lower urinary tract symptom (LUTs) for subjective assessment and urodynamic study for objective assessment. RESULTS: A total of 60 patients were enrolled, of whom 30 received RSC and 30 received TVM. In LUTs analysis, the RSC group had a higher risk of de novo stress urinary incontinence than the TVM group (33.3% vs. 3.3%, p = .007). Urodynamic studies showed that both groups had a deterioration in maximal urethral closure pressure postoperatively (RSC: 56.9 ± 17.1 vs. 44.2 ± 15.5 cmH2O; and TVM: 61.2 ± 29.4 vs. 47.6 ± 19.7 cmH2O, p < .01 and p = .03, respectively). The incidence of urodynamic stress incontinence was also significantly increased after RSC (33.3% vs. 76.7%, p = .01). The de novo urodynamic stress incontinence rate was 46.7% after RSC, which was not significantly different to the TVM group (26.7%, p = .16). In the TVM group, the incidence of voiding difficulty decreased after surgery (43.3% vs. 10.0%, p < .01), and urodynamic measurements revealed that the prevalence of urine retention decreased (43.3% vs. 16.7%, p < .01). In the RSC group, the incidence of incomplete emptying sensation decreased (36.7% vs. 13.3%, p = .04), and urodynamic measurements showed that none of the patients had bladder outlet obstruction, underactive detrusor, or urine retention after surgery. CONCLUSION: RSC and TVM are both beneficial to improve voiding function in women with pelvic organ prolapse. However, a deterioration in urethral function was observed and the de novo SUI rate was higher in the RSC group than in the TVM group.


Assuntos
Sintomas do Trato Urinário Inferior , Prolapso de Órgão Pélvico , Robótica , Incontinência Urinária por Estresse , Retenção Urinária , Humanos , Feminino , Bexiga Urinária/cirurgia , Telas Cirúrgicas/efeitos adversos , Estudos Prospectivos , Incontinência Urinária por Estresse/etiologia , Incontinência Urinária por Estresse/cirurgia , Sintomas do Trato Urinário Inferior/complicações , Prolapso de Órgão Pélvico/complicações , Retenção Urinária/epidemiologia , Retenção Urinária/etiologia
3.
Foods ; 11(4)2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35205976

RESUMO

Although the safety of commercial genetically modified (GM) soybeans has been well evaluated and GM soybeans are legally sold under government management, some consumers still have concerns about their safety. The objective of this study was to evaluate the safety of commercial GM soybeans sold in markets as a food source. In the present study, two commercial GM (GM-1 and -2) soybeans and one non-GM soybean were randomly purchased and subjected to a whole food toxicity assessment. Rats (SD), male and female, were divided into six groups (10/sex/group). Two dosages of 1 g/kg/day and 5 g/kg/day of soybeans were selected for the low- and high-dose groups. Rats were administered the soybeans via daily oral fed for 90 days. The results indicate that the body weight, organ weight, biochemistry, hematology, and urology showed no biologically adverse effects. At necropsy, no significant differences between organ weights were noted between the non-GM- and GM soybeans-treated groups. Moreover, no gross or histopathological lesions were observed in the high-dosage (5 g/kg/day) fed groups of the non-GM and GM soybean fed rats. In conclusion, this food safety assessment revealed that commercial GM soybeans are substantially equivalent to non-GM soybeans in rats.

4.
Colloids Surf B Biointerfaces ; 209(Pt 1): 112152, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34655983

RESUMO

The management of contact lens discomfort remains a challenge leading to the increased contact lens dropout rates. Tear protein accumulates on the lens surfaces with different configurations observed are correlated to the lens friction, with the improved comfort experienced by reduced surface friction in the eye. However, protein adsorption is a complex process with the combined protein-protein interactions (PPI) and protein-surface interactions (PSI) involved, which is difficult to explain the complicated tribological behavior in terms of protein structural shifts alone on lens surfaces. On the other hand, the type of solvent-exposed side chains from specific protein conformations on lens surfaces should be more important to the lens friction involved. We aim to investigate the correlation between the structure-related side-chain exposure and corresponding lens friction of adsorbed tear proteins on lens surfaces under varied PPI and PSI. Albumin was the model protein adsorbed onto the conventional lens material. Such as polymethylmethacrylate (PMMA) or the poly-2-hydroxyethyl methacrylate (PHEMA) surfaces applied here. Adsorption was conducted under varying protein solution concentrations to saturate the model surface to change the PPI effects over a wide range. Our results indicate that PPI effects help stabilize protein structures on both surfaces. When PPI is minimized, a distinct correlation was observed between the surface friction and the hydrophobicity of structure-related side-chain exposure of albumin on lens surfaces depending on the different PSI involved. At a fundamental understanding, our results would provide insights for developing new lens materials or the lens care solution designs to reduce the lens discomfort.


Assuntos
Lentes de Contato , Albuminas , Fricção , Hidrogéis , Interações Hidrofóbicas e Hidrofílicas
6.
Chemosphere ; 262: 128249, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182142

RESUMO

Saltwater fish is rich in health-promoting polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Excessive fish intake may also cause health hazards due to methylmercury (MeHg). A novel dose estimation method was proposed in this study to improve the quality of food matching by considering the usage ratio of cooking and processing methods in sampling design. In total, 39 table-ready samples were specified according to 2-3 common cooking methods, and MeHg and total mercury (THg) were analyzed. The results showed that mercury was detected in 20 samples (LOD = 0.01 µg/g). High MeHg samples included fried-Spanish mackerel (1.23 µg/g), non-cooked shredded swordfish (0.325 µg/g), pan-fried Spanish mackerel (0.248 µg/g), and non-cooked shredded salmon (0.208 µg/g). Consumption data (n = 166,911) were obtained from 24-h recalls in the 2005-2008 Nutrition and Health Surveys in Taiwan (NAHSIT). The average whole-group estimated daily intake (EDI_WG) was 0.018 (7.9% tolerable daily intake, TDI) for women of child-bearing age and 0.031 µg/day per kg body weight (13.6% TDI) for children. However, 95th percentile values (P95) of 90.4% TDI and 185% TDI were estimated for the two consumer-only populations, which have raised public health concerns. The ratio of % TDI to % daily reference intake (% DRI) was used as a risk-benefit (R/B) indicator. The top 4 R/B foods were: tuna sashimi (0.089 and 0.14), non-cooked shredded swordfish (0.033 and 0.052), fried-Spanish mackerel (0.027 and 0.043) and deep-fried fish balls (0.022 and 0.035) in the two perspective populations.


Assuntos
Exposição Dietética/análise , Ácidos Graxos Insaturados/análise , Peixes/metabolismo , Compostos de Metilmercúrio/análise , Alimentos Marinhos/análise , Adulto , Animais , Criança , Culinária , Ácidos Docosa-Hexaenoicos/análise , Ácido Eicosapentaenoico/análogos & derivados , Ácido Eicosapentaenoico/análise , Feminino , Humanos , Pessoa de Meia-Idade , Saúde Pública , Medição de Risco , Taiwan
7.
Polymers (Basel) ; 12(8)2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32717989

RESUMO

The ocular discomfort is the leading cause of contact lens wear discontinuation. Although the tear proteins as a lubricant might improve contact lens adaptation, some in vitro studies suggested that the amount of adsorbed proteins could not simply explain the lubricating performance of adsorbed proteins. The purpose of this study was to quantify the structural changes and corresponding ocular lubricating properties of adsorbed protein on a conventional contact lens material, poly (2-hydroxyethyl methacrylate) (pHEMA). The adsorption behaviors of lysozyme on pHEMA were determined by the combined effects of protein-surface and protein-protein interactions. Lysozyme, the most abundant protein in tear, was first adsorbed onto the pHEMA surface under widely varying protein solution concentrations to saturate the surface, with the areal density of the adsorbed protein presenting different protein-protein effects within the layer. These values were correlated with the measured secondary structures, and corresponding friction coefficient of the adsorbed and protein covered lens surface, respectively. The decreased friction coefficient value was an indicator of the lubricated surfaces with improved adaptation. Our results indicate that the protein-protein effects help stabilize the structure of adsorbed lysozyme on pHEMA with the raised friction coefficient measured critical for the innovation of contact lens material designs with improved adaptation.

8.
Polymers (Basel) ; 12(8)2020 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-32722491

RESUMO

Dental ceramic material is one of the widely preferred restorative materials to mimic the natural tooth enamel surface. However, it has continuously been degraded because of low wear resistance during mastication in the oral cavity. The friction involved was reduced by introducing the lubricant saliva protein layers to improve the wear resistance of the dental materials. However, little is understood regarding how the protein-protein interactions (PPI) influence the adsorbed-state structures and lubricating behaviors of saliva proteins on the ceramic material surface. The objective of this study is to quantify the influences of PPI effects on the structural changes and corresponding oral lubrications of adsorbed α-amylase, one of the abundant proteins in the saliva, on the dental ceramic material with glass as a model surface. α-Amylase was first adsorbed to glass surface under varying protein solution concentrations to saturate the surface to vary the PPI effects over a wide range. The areal density of the adsorbed protein was measured as an indicator of the level of PPI effects within the layer, and these values were then correlated with the measurements of the adsorbed protein's secondary structure and corresponding friction coefficient. The decreased friction coefficient value was an indicator of the lubricated surfaces with higher wear resistance. Our results indicate that PPI effects help stabilize the structure of α-amylase adsorbed on glass, and the correlation observed between the friction coefficient and the conformational state of adsorbed α-amylase was apparent. This study thus provides new molecular-level insights into how PPI influences the structure and lubricating behaviors of adsorbed protein, which is critical for the innovations of dental ceramic material designs with improved wear resistance.

9.
Artigo em Inglês | MEDLINE | ID: mdl-32443497

RESUMO

Debulking surgery followed by systemic chemotherapy-including three-weekly intravenous paclitaxel and carboplatin (GOG-158)-is the cornerstone for advanced epithelial ovarian, fallopian tubal, and peritoneal cancer (EOC) treatment. In this scenario, Federation of Gynecology and Obstetrics (FIGO) stage, cell types, completeness of surgery, lymph nodes (LN) status, adjuvant chemotherapy regimens, survival status, progression-free survival (PFS), and overall survival (OS) of 192 patients diagnosed as having stage IIIA1-IVB EOC over January 2008-December 2017 were analyzed retrospectively. Of them, 100 (52.1%) patients had been debulked optimally. Of all cases, 64.1% and 10.9% demonstrated serous and clear-cell carcinoma. Moreover, the FIGO stage, surgery completeness, and LN status affected recurrence/persistence and mortality (all p < 0.001). Clear cell carcinoma led to shorter survival than serous carcinoma (p = 0.002). Adjuvant chemotherapy regimens were divided into five main groups according to previous clinical trials. However, choice of chemotherapy failed to demonstrate significant differences in patient outcomes. Similar results were found in the sub-analysis of optimally debulked cases, except that intraperitoneal chemotherapy could reduce mortality risk when compared with GOG-158 (p = 0.042). Notably, retroperitoneal LN dissection in all cases or optimally debulked cases reduced risks of recurrence/persistence and mortality, and prolonged PFS and OS significantly (all p < 0.05). Without optimal debulking, LN dissection led to little improvement in outcomes. Various modified chemotherapy regimens did not prolong PFS and OS or reduce recurrence/persistence and mortality risks. LN dissection is strongly recommended to improve the completeness of surgery and patient outcome. Clear cell type has a poorer outcome than serous type, which requires more aggressive treatment and follow-up.


Assuntos
Quimioterapia Adjuvante , Neoplasias das Tubas Uterinas , Neoplasias Ovarianas , Neoplasias Peritoneais , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias das Tubas Uterinas/tratamento farmacológico , Neoplasias das Tubas Uterinas/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/cirurgia , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Peritoneais/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
10.
BMC Cancer ; 20(1): 310, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32293339

RESUMO

BACKGROUND: Cancer development is mediated by oxidative stress and inflammation, which may correlate with metabolic disorders. The aim of this study was to evaluate antioxidant vitamins status and metabolic parameters in patients with oral cancer according to tumor-node-metastasis (TNM) stages. METHODS: A total of 194 patients with oral cancer were enrolled in this study. The patients were stratified for four groups according to cancer stages and that the statistics are comparisons across these groups. The levels of antioxidant vitamins (ubiquinone, ß-carotene, vitamin A and E), metabolic parameters, oxidative stress, antioxidant enzymes activity, and inflammatory markers were measured. RESULTS: More than half of the subjects had high blood pressure, central obesity, hyperglycemia, and hyperlipidemia regardless of TNM stage. With regard to antioxidant vitamins status, 46 and 94% of patients had ß-carotene and ubiquinone deficiency, respectively. Patients in T3 and T4 stages had significantly lower antioxidant enzyme (catalase, p = 0.03) activity and higher inflammatory markers levels (high sensitivity C-reactive protein and interleukin-6, p < 0.01) than patients in the other stages. In addition, the level of ß-carotene was negatively associated with waist circumference, and ubiquinone was positively associated with the level of high-density lipoprotein cholesterol (p < 0.05). Higher ß-carotene and ubiquinone levels were negatively associated with hypertriglyceridemia and the risk of metabolic syndrome (p < 0.05). CONCLUSIONS: A high proportion of patients with oral cancer had ubiquinone or ß-carotene deficiency and metabolic disorders. The level of ubiquinone or ß-carotene was negatively associated with the risk of central obesity, hypertriglyceridemia, and metabolic syndrome. Since patients with oral cancer suffer from high oxidative stress and inflammation (particularly in the T3 and T4 stages), supplementation with antioxidant vitamins such as ubiquinone or ß-carotene could be preferentially applied.


Assuntos
Doenças Metabólicas/epidemiologia , Neoplasias Bucais/patologia , Ubiquinona/deficiência , beta Caroteno/deficiência , Adulto , Idoso , Proteína C-Reativa/metabolismo , Estudos Transversais , Feminino , Humanos , Interleucina-6/sangue , Masculino , Doenças Metabólicas/sangue , Doenças Metabólicas/classificação , Pessoa de Meia-Idade , Neoplasias Bucais/sangue , Estadiamento de Neoplasias , Estresse Oxidativo , Vitamina A/sangue , Vitamina E/sangue
11.
Bioinformatics ; 35(19): 3761-3770, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30851108

RESUMO

MOTIVATION: The concept of synergy between two agents, over a century old, is important to the fields of biology, chemistry, pharmacology and medicine. A key step in drug combination analysis is the selection of an additivity model to identify combination effects including synergy, additivity and antagonism. Existing methods for identifying and interpreting those combination effects have limitations. RESULTS: We present here a computational framework, termed response envelope analysis (REA), that makes use of 3D response surfaces formed by generalized Loewe Additivity and Bliss Independence models of interaction to evaluate drug combination effects. Because the two models imply two extreme limits of drug interaction (mutually exclusive and mutually non-exclusive), a response envelope defined by them provides a quantitatively stringent additivity model for identifying combination effects without knowing the inhibition mechanism. As a demonstration, we apply REA to representative published data from large screens of anticancer and antibiotic combinations. We show that REA is more accurate than existing methods and provides more consistent results in the context of cross-experiment evaluation. AVAILABILITY AND IMPLEMENTATION: The open-source software package associated with REA is available at: https://github.com/4dsoftware/rea. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Biologia Computacional , Software , Combinação de Medicamentos , Interações Medicamentosas
12.
Phys Rev Lett ; 121(10): 106801, 2018 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-30240231

RESUMO

The existence of Wigner crystallization, one of the most significant hallmarks of strong electron correlations, has to date only been definitively observed in two-dimensional systems. In one-dimensional (1D) quantum wires Wigner crystals correspond to regularly spaced electrons; however, weakening the confinement and allowing the electrons to relax in a second dimension is predicted to lead to the formation of a new ground state constituting a zigzag chain with nontrivial spin phases and properties. Here we report the observation of such zigzag Wigner crystals by use of on-chip charge and spin detectors employing electron focusing to image the charge density distribution and probe their spin properties. This experiment demonstrates both the structural and spin phase diagrams of the 1D Wigner crystallization. The existence of zigzag spin chains and phases which can be electrically controlled in semiconductor systems may open avenues for experimental studies of Wigner crystals and their technological applications in spintronics and quantum information.

13.
Oxid Med Cell Longev ; 2018: 9303094, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29951168

RESUMO

Oral cancer is the fifth leading cause of cancer death in Taiwan, and the prevalence of metabolic syndrome (MS) has also increased globally. The purpose of this study was to investigate the correlations between the components of MS and oxidative stress and inflammation in patients with oral cancer based on their areca-nut-chewing habits. Two hundred patients diagnosed with oral cancer were recruited, and metabolic parameters, oxidative stress, antioxidant enzyme activities, and inflammatory markers were measured. 63% of the subjects have concomitant MS. Subjects who had an areca-nut-chewing habit had significantly higher levels of fasting glucose (p = 0.04), oxidative stress (p = 0.02), and inflammatory markers (p = 0.02) than those who never chewed. High-density lipoprotein-cholesterol level (p = 0.03) and superoxidase dismutase activity (p = 0.02) were significantly lower in individuals who had chewed or were currently chewers. Areca-nut-chewing habit was associated with the increased risks for MS and hypertriglyceridemia; the components of MS were positively correlated with oxidative stress and inflammation. In conclusion, patients with oral cancer who had an areca-nut-chewing habit exhibited higher levels of oxidative stress and inflammation, which might be related to an increased risk of MS.


Assuntos
Areca/efeitos adversos , Inflamação/complicações , Síndrome Metabólica/complicações , Neoplasias Bucais/etiologia , Estresse Oxidativo/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , Fatores de Risco , Adulto Jovem
14.
IEEE Trans Biomed Circuits Syst ; 11(6): 1216-1225, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29293419

RESUMO

Next-generation sequencing (NGS) enables high-throughput sequencing, in which short DNA fragments can be sequenced in a massively parallel fashion. However, the essential algorithm behind the succeeding NGS data analysis, DNA mapping, is still excessively time consuming. DNA mapping can be partitioned into two parts: suffix array (SA) sorting and backward searching. Dedicated hardware designs for the less-complex backward searching have been proposed, but feasible hardware for the most complicated part, SA sorting, has never been explored. Based on the memory-efficient sBWT algorithm, this work is the first integrated NGS data processor for the entire DNA mapping. The -ordered Ferragina and Manzini index used in the sBWT algorithm is leveraged to improve storage capacity and reduce hardware complexity. The proposed NGS data processor realizes the sBWT algorithm through bucket sorting, suffix grouping, and suffix sorting circuits. Key design parameters are analyzed to achieve the optimal performance with respect to hardware cost and execution time. Fabricated in 40-nm CMOS, the NGS data processor dissipates 135 mW at 200 MHz from a 0.9-V supply. With 1-GB external memory, the chip can analyze human DNA within 10 min. This work achieves 43 065 and 8 971 [3208 and 402 ] higher energy efficiency (throughput-to-area ratio) than the high-end CPU and GPU solutions, respectively.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Processamento de Sinais Assistido por Computador , Algoritmos , Desenho de Equipamento , Humanos , Análise de Sequência de DNA/métodos , Software
15.
Bioinformatics ; 32(22): 3498-3500, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27412087

RESUMO

MOTIVATION: The Full-text index in Minute space (FM-index) derived from the Burrows-Wheeler transform (BWT) is broadly used for fast string matching in large genomes or a huge set of sequencing reads. Several graphic processing unit (GPU) accelerated aligners based on the FM-index have been proposed recently; however, the construction of the index is still handled by central processing unit (CPU), only parallelized in data level (e.g. by performing blockwise suffix sorting in GPU), or not scalable for large genomes. RESULTS: To fulfill the need for a more practical, hardware-parallelizable indexing and matching approach, we herein propose sBWT based on a BWT variant (i.e. Schindler transform) that can be built with highly simplified hardware-acceleration-friendly algorithms and still suffices accurate and fast string matching in repetitive references. In our tests, the implementation achieves significant speedups in indexing and searching compared with other BWT-based tools and can be applied to a variety of domains. AVAILABILITY AND IMPLEMENTATION: sBWT is implemented in C ++ with CPU-only and GPU-accelerated versions. sBWT is open-source software and is available at http://jhhung.github.io/sBWT/Supplementary information: Supplementary data are available at Bioinformatics online. CONTACT: chyee@ntu.edu.tw or jhhung@nctu.edu.tw (also juihunghung@gmail.com).


Assuntos
Algoritmos , Software , Indexação e Redação de Resumos , Genoma , Humanos
16.
Nanotechnology ; 26(21): 215703, 2015 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-25943071

RESUMO

Designing various inorganic nanomaterials that are cost effective, water soluble, optically photostable, highly fluorescent and biocompatible for bioimaging applications is a challenging task. Similar to semiconducting quantum dots (QDs), silicon QDs are another alternative and are highly fluorescent, but non-water soluble. Several surface modification strategies were adopted to make them water soluble. However, the photoluminescence of Si QDs was seriously quenched in the aqueous environment. In this report, highly luminescent, water-dispersible, blue- and green-emitting Si QDs were prepared with good photostability. In vitro studies in monocytes reveal that Si QDs exhibit good biocompatibility and excellent distribution throughout the cytoplasm region, along with the significant fraction translocated into the nucleus. The in vivo zebrafish studies also reveal that Si QDs can be evenly distributed in the yolk-sac region. Overall, our results demonstrate the applicability of water-soluble and highly fluorescent Si QDs as excellent in vitro and in vivo bioimaging probes.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Meios de Contraste/química , Meios de Contraste/toxicidade , Pontos Quânticos/química , Pontos Quânticos/toxicidade , Animais , Materiais Biocompatíveis/farmacocinética , Células Cultivadas , Meios de Contraste/farmacocinética , Substâncias Luminescentes/química , Substâncias Luminescentes/farmacocinética , Substâncias Luminescentes/toxicidade , Medições Luminescentes , Teste de Materiais , Camundongos Endogâmicos C57BL , Monócitos/efeitos dos fármacos , Silício/química , Silício/farmacocinética , Solubilidade , Água , Peixe-Zebra
17.
Opt Express ; 20 Suppl 4: A441-51, 2012 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-22828613

RESUMO

Indium-tin-oxide (ITO) nanowhiskers with attractive electrical and anti-reflection properties were prepared by the glancing-angle electron-beam evaporation technique. Structural and crystalline properties of such nanostructures were examined by scanning transmission electron microscopy and X-ray diffraction. Their frequency-dependent complex conductivities, refractive indices and absorption coefficients have been characterized with terahertz time-domain spectroscopy (THz-TDS), in which the nanowhiskers were considered as a graded-refractive-index (GRIN) structure instead of the usual thin film model. The electrical properties of ITO GRIN structures are analyzed and fitted well with Drude-Smith model in the 0.2~2.0 THz band. Our results indicate that the ITO nanowhiskers and its bottom layer atop the substrate exhibit longer carrier scattering times than ITO thin films. This signifies that ITO nanowhiskers have an excellent crystallinity with large grain size, consistent with X-ray data. Besides, we show a strong backscattering effect and fully carrier localization in the ITO nanowhiskers.

18.
Opt Express ; 19 Suppl 5: A1141-7, 2011 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-21935257

RESUMO

The enhanced efficiency of the crystalline silicon (c-Si) solar cell with nanopillar arrays (NPAs) was demonstrated by deployment of CdS quantum dots (QDs). The NPAs was fabricated by the colloidal lithography and reactive-ion etching techniques. Under a simulated one-sun condition, the device with CdS QDs shows a 33% improvement of power conversion efficiency, compared with the one without QDs. For further investigation, the excitation spectrum of photoluminescence (PL), absorbance spectrum, current-voltage (I-V) characteristics, reflectance and external quantum efficiency of the device was measured and analyzed. It is noteworthy that the enhancement of efficiency could be attributed to the photon down-conversion, the antireflection, and the improved electrical property.

19.
Opt Express ; 19 Suppl 3: A219-24, 2011 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-21643363

RESUMO

Omnidirectional and broadband light harvesting is critical to photovoltaics due to the sun's movement and its wide spectral range of radiation. In this work, we demonstrate distinctive indium-tin-oxide nanowhiskers that achieve superior angular and spectral characteristics for crystalline silicon solar cells using angle-resolved reflectance spectroscopy. The solar-spectrum weighted reflectance is well below 6% for incident angles of up to 70° and for the wavelength range between 400nm and 1000nm. As a result, the nanowhisker coated solar cell exhibits broadband quantum efficiency characteristics and enhanced short-circuit currents for large angles of incidence.

20.
Nanotechnology ; 22(9): 095201, 2011 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-21258142

RESUMO

As silicon photovoltaics evolve towards thin-wafer technologies, efficient optical absorption for the near-infrared wavelengths has become particularly challenging. In this work, we present a solution that employs combined micro- and nano-scale surface textures to increase light harvesting in the near-infrared for crystalline silicon photovoltaics, and discuss the associated antireflection and scattering mechanisms. The surface textures are achieved by uniformly depositing a layer of indium-tin-oxide nanowhiskers on micro-grooved silicon substrates using electron-beam evaporation. The nanowhiskers facilitate optical transmission in the near-infrared by functioning as impedance matching layers with effective refractive indices gradually varying from 1 to 1.3. Materials with such unique refractive index characteristics are not readily available in nature. As a result, the solar cell with combined textures achieves over 90% external quantum efficiencies for a broad wavelength range of 460-980 nm, which is crucial to the development of advanced thin-substrate silicon solar cells.


Assuntos
Fontes de Energia Elétrica , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Nanotecnologia/instrumentação , Silício/química , Energia Solar , Cristalização/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Raios Infravermelhos , Luz , Teste de Materiais , Propriedades de Superfície
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