Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 89
Filtrar
1.
J Am Chem Soc ; 142(41): 17681-17692, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32924464

RESUMO

Conjugated polymers are regarded as promising candidates for dopant-free hole-transport materials (HTMs) in efficient and stable perovskite solar cells (PSCs). Thus far, the vast majority of polymeric HTMs feature structurally complicated benzo[1,2-b:4,5-b']dithiophene (BDT) analogs and electron-withdrawing heterocycles, forming a strong donor-acceptor (D-A) structure. Herein, a new class of phenanthrocarbazole (PC)-based polymeric HTMs (PC1, PC2, and PC3) has been synthesized by inserting a PC unit into a polymeric thiophene or selenophene chain with the aim of enhancing the π-π stacking of adjacent polymer chains and also to efficiently interact with the perovskite surface through the broad and planar conjugated backbone of the PC. Suitable energy levels, excellent thermostability, and humidity resistivity together with remarkable photoelectric properties are obtained via meticulously tuning the conformation and elemental composition of the polymers. As a result, PSCs containing PC3 as dopant-free HTM show a stabilized power conversion efficiency (PCE) of 20.8% and significantly enhanced longevity, rendering one of the best types of PSCs based on dopant-free HTMs. Subsequent experimental and theoretical studies reveal that the planar conformation of the polymers contributes to an ordered and face-on stacking of the polymer chains. Furthermore, introduction of the "Lewis soft" selenium atom can passivate surface trap sites of perovskite films by Pb-Se interaction and facilitate the interfacial charge separation significantly. This work reveals the guiding principles for rational design of dopant-free polymeric HTMs and also inspires rational exploration of small molecular HTMs.

2.
J Am Chem Soc ; 141(50): 19700-19707, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31747277

RESUMO

Perovskite solar cells (PSCs) has skyrocketed in the past decade to an unprecedented level due to their outstanding photoelectric properties and facile processability. However, the utilization of expensive hole transport materials (HTMs) and the inevitable instability instigated by the deliquescent dopants represent major concerns hindering further commercialization. Here, a series of low-cost, conjugated polymers are designed and applied as dopant-free HTMs in PSCs, featuring tuned energy levels, good temperature and humidity resistivity, and excellent photoelectric properties. Further studies highlight the critical and multifaceted roles of the polymers with respect to facilitating charge separation, passivating the surface trap sites of perovskite materials, and guaranteeing long-term stability of the devices. A stabilized power conversion efficiency (PCE) of 20.3% and remarkably enhanced device longevity are achieved using the dopant-free polymer P3 with a low concentration of 5 mg/mL, qualifying the device as one of the best PSC systems constructed on the basis of dopant-free HTMs so far. In addition, the flexible PSCs based on P3 also exhibit a PCE of 16.2%. This work demonstrates a promising route toward commercially viable, stable, and efficient PSCs.

3.
Infection ; 46(5): 705-710, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29737456

RESUMO

BACKGROUND: Disseminated nocardiosis is a rare disease mostly occurring in immunocompromised patients. METHODS: We report a case of disseminated nocardiosis in a diabetic patient with both pulmonary and cutaneous involvement. Nocardia elegans was isolated and identified using the 16s ribosomal RNA gene sequence data. RESULTS: Clinical improvement was observed within 3 months after initiation of antimicrobial treatment with oral doxycycline, trimethoprim-sulfamethoxazole and intravenous penicillin, but the patient died 5 months later after arbitrary discontinuation of the treatment. CONCLUSIONS: This is the first case report of disseminated nocardiosis caused by Nocardia elegans in China.


Assuntos
Nocardiose/diagnóstico , Nocardiose/microbiologia , Nocardia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Evolução Fatal , Feminino , Humanos , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Nocardia/classificação , Nocardia/efeitos dos fármacos , Nocardia/genética , Nocardia/isolamento & purificação , Nocardiose/tratamento farmacológico , Filogenia , Pneumonia Bacteriana/diagnóstico , Pneumonia Bacteriana/microbiologia , RNA Bacteriano , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Dermatopatias Bacterianas/microbiologia , Dermatopatias Bacterianas/patologia
4.
Dermatol Surg ; 43(3): 437-442, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28099200

RESUMO

BACKGROUND: Medical photography is increasingly used by physicians, but studies assessing the perception and acceptability of medical photography by Chinese dermatologic patients are scarce. OBJECTIVE: To assess the perception and acceptability of medical photography in Chinese dermatologic patients. MATERIALS AND METHODS: From July to December 2014, adult patients visiting the Dermatology Clinic of The First Affiliated Hospital of Third Military Medical University were included in this study. They were required to fill an anonymous questionnaire regarding perception and acceptability of medical photography. RESULTS: A total of 509 consecutive patients completed the questionnaire, with 35 and 474 declining and undergoing medical photography, respectively. Meanwhile, 81.0% of the patients preferred to be photographed by attending physicians; 63.3% favored clinic-owned cameras, and 81.0% would rather have their photographs stored in the department's database. Besides, most patients allowed their photographs to be used in case studies (92.8%) or medical record keeping (90.3%). CONCLUSION: Most Chinese dermatologic patients accept medical photography. However, the principles of privacy protection and informed consent should be strictly enforced in clinical practice, and appropriate photographic devices and storage methods should be used, for better acceptance.


Assuntos
Povo Asiático , Dermatologia , Consentimento Livre e Esclarecido , Preferência do Paciente/etnologia , Fotografação , Dermatopatias/etnologia , Percepção Social , Inquéritos e Questionários , Adolescente , Adulto , Idoso , Povo Asiático/estatística & dados numéricos , Atitude , China/epidemiologia , Confidencialidade , Dermatologia/instrumentação , Feminino , Hospitais Militares , Humanos , Consentimento Livre e Esclarecido/estatística & dados numéricos , Masculino , Prontuários Médicos , Pessoa de Meia-Idade , Propriedade/estatística & dados numéricos , Fotografação/instrumentação , Fotografação/métodos , Fotografação/estatística & dados numéricos , Privacidade/psicologia , Estudos Retrospectivos , Dermatopatias/psicologia , Estigma Social
6.
Mycopathologia ; 179(5-6): 447-52, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25575792

RESUMO

Chromoblastomycosis is a chronic subcutaneous mycosis caused by dematiaceous fungi. Fonsecaea monophora, a new species segregated from F. pedrosoi, may be the most prevalent pathogen of chromoblastomycosis in southern China. Herein, we report a rare case of chromoblastomycosis in a man with nephritic syndrome. He presented with an asymptomatic red plaque on the back of his left wrist that had appeared and enlarged over a period of 1.5 years, without any prior trauma. He was initially diagnosed with sporotrichosis. However, he did not respond to a 6-month course of potassium iodide treatment. The lesion slowly enlarged and became verrucous instead. Concurrently, a similar maculopapule appeared on his left forearm. Histopathological examination of a biopsy specimen indicated the presence of sclerotic bodies in the dermis. The fungus was identified as Fonsecaea spp. based on the results of a slide culture; in addition, the agent was confirmed to be F. monophora by using molecular methods. The patient demonstrated marked improvement after receiving appropriate antifungal therapy for 3 months. To our knowledge, this is the first case of chromoblastomycosis caused by F. monophora in an immunosuppressed patient. The identification of the agent by molecular techniques is important for epidemiological purposes. Thus, we believe that combination therapy with itraconazole and terbinafine would be a suitable option for infections caused by F. monophora.


Assuntos
Ascomicetos/isolamento & purificação , Cromoblastomicose/diagnóstico , Cromoblastomicose/microbiologia , Nefropatias/complicações , Antifúngicos/uso terapêutico , Ascomicetos/classificação , Biópsia , China , Cromoblastomicose/tratamento farmacológico , Cromoblastomicose/patologia , Antebraço/patologia , Histocitoquímica , Humanos , Masculino , Técnicas Microbiológicas , Microscopia , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Resultado do Tratamento , Punho/patologia
7.
Zhonghua Bing Li Xue Za Zhi ; 44(2): 100-5, 2015 Feb.
Artigo em Zh | MEDLINE | ID: mdl-25916640

RESUMO

OBJECTIVE: To study the clinicopathologic features, immunophenotype and gene rearrangement of primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL). METHODS: Seven cases of PCLBCL were enrolled into the study. Clinicopathologic analysis, immunohistochemical staining and gene rearrangement for IgH and Igκ were undertaken in the study. RESULTS: All the seven cases were male, and the median age was 72 years. Patients usually presented with multiple purple tumors, nodules, papules and infiltrative plaques. Two patients had a history of leg injury before onset, and one had mosquito bites. Histologically, the tumor involved the dermis and subcutis with dense and diffuse infiltrative pattern composing of centroblasts and/or immunoblasts. Immunohistochemical staining showed that seven cases (7/7) expressed CD20, six (6/6) expressed bcl-2, four (4/4) expressed MUM-1, four (4/5) expressed CD79a, four (4/5) expressed PAX-5 and four (4/6) expressed bcl-6, respectively. All cases did not express CD3ε, CD45RO, CD10 and CD30. IgH gene rearranged bands were detected in three (3/6) cases and Igκ was detected in one (1/5) case. Six of the seven cases died and the remaining patient, who was 44-year-old, was alive after 22 months of follow-up. CONCLUSIONS: PCLBCL is rare, predominantly affects elderly male patients. PCLBCL has poor prognosis and high mortality, but younger patients seem to have better prognosis. Some cases had a history of trauma or mosquito bites. The relationship between the history and the onset of PCLBCL needs further evaluation.


Assuntos
Rearranjo Gênico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Idoso , Idoso de 80 Anos ou mais , Animais , Antígenos CD/análise , Culicidae , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias kappa de Imunoglobulina/genética , Imunofenotipagem , Mordeduras e Picadas de Insetos/complicações , Perna (Membro) , Traumatismos da Perna/complicações , Linfoma Difuso de Grandes Células B/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo
8.
Biochim Biophys Acta ; 1833(10): 2190-200, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23688634

RESUMO

Transcription factor FOXP3 (forkhead box P3) is found initially as a key regulator in regulatory T cells. Recently its expression has been demonstrated in some non-lymphoid normal and cancerous cells. Now FOXP3 has been proven to regulate cancer-related genes, especially suppressor genes in breast cancer. But the mechanisms by which FOXP3 regulates suppressor genes are not fully determined. In this study, we found the inverse correlation between FOXP3 and Ezh2, an enzyme for histone H3K27 trimethylation (H3K27me3) and a central epigenetic regulator in cancer. The overexpression of FOXP3 weakened Ezh2's enhancement on the mammosphere formation, cell proliferation, directional migration, and colony forming ability of T47D cells. We demonstrated that FOXP3 could downregulate Ezh2 protein level and this depended on not only the FOXP3 expression amount, but also the nuclear localization of FOXP3. More importantly, we demonstrated FOXP3 accelerated Ezh2 protein degradation through the polyubiquitination-proteasome pathway by enhancing the transcription of E3 ligase Praja1 directly. These results provided a new mechanism for FOXP3 in histone modifications as an Ezh2 suppressor and supported new evidence for FOXP3 as a tumor suppressor in breast cancer.


Assuntos
Neoplasias da Mama/genética , Montagem e Desmontagem da Cromatina/genética , Fatores de Transcrição Forkhead/metabolismo , Regulação Neoplásica da Expressão Gênica , Complexo Repressor Polycomb 2/genética , Animais , Animais Recém-Nascidos , Western Blotting , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Movimento Celular , Proliferação de Células , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias , Proteína Potenciadora do Homólogo 2 de Zeste , Epigenômica , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Imunofluorescência , Fatores de Transcrição Forkhead/genética , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Pulmão/citologia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Complexo Repressor Polycomb 2/metabolismo , Poliubiquitina/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas/genética , Proteínas/metabolismo , Proteólise , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Cicatrização
9.
J Cancer Res Clin Oncol ; 150(4): 217, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38668799

RESUMO

PURPOSE: Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin, which mainly occurs in the sun exposed sites of white patients over 65 years, with a higher recurrence and metastasis rate. Clinically, MCC overlapping Bowen's disease (BD) is a very rare subtype of MCC. Few cases in the literature have been described and the management is not well defined. We summarize and update the epidemiology, clinical and histopathological features, metastasis characteristics, local recurrence rate and management of it by presenting two cases of MCC overlapping BD and reviewing the literature over the last 11 years. DESIGN: We consulted databases from PubMed, ResearchGate and Google Scholar by MeSh "Merkel cell carcinoma" and "Bowen's disease", "Bowen disease" or "squamous cell carcinoma in situ", from January 2013 to December 2023 and reviewed the literatures. We reported two additional cases. RESULTS: Total 13 cases of MCC overlapping BD were retrospectively analyzed, in whom mainly in elderly women over 70 years, the skin lesions were primarily located on the faces, followed by the extremities and trunk. Most of them were asymptomatic, firm, dark red nodules arising on rapidly growing red or dark brown patches, or presenting as isolated nodules. Dermoscopy evaluation was rarely performed in the pre-operative diagnostic setting. All cases were confirmed by histopathology and immunohistochemistry. The most definitive treatment was extended local excision, but local recurrences were common. Of the 13 cases, 4 cases experienced local or distant metastasis. One suffered from an in-transit recurrence of MCC on the ipsilateral leg after local excision and lymph node dissection, whose metastasis completely subsided after avelumab treatment and without recurrence or metastasis during 6 months of follow-up. CONCLUSIONS: MCC overlapping BD is a very rare skin tumor mainly predisposed on the faces, with high misdiagnosis rate and recurrence rate. Advanced disease at diagnosis is a poor prognostic factor, suggesting that earlier detection may improve outcome. The acronym, AEIOUN, has been proposed to aid in clinical identification. Our reports and the literature review can provide a better awareness and management of it.


Assuntos
Doença de Bowen , Carcinoma de Célula de Merkel , Neoplasias Cutâneas , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Bowen/patologia , Doença de Bowen/diagnóstico , Doença de Bowen/terapia , Carcinoma de Célula de Merkel/patologia , Carcinoma de Célula de Merkel/terapia , Carcinoma de Célula de Merkel/diagnóstico , Recidiva Local de Neoplasia/patologia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/diagnóstico
10.
J Phys Chem Lett ; 15(26): 6750-6757, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38912792

RESUMO

Colloidal quantum dots (CQDs) have garnered considerable attention for photodetectors (PDs), attributable to exceptional photoelectric properties and ease solution-based processing. However, the prevalent use of 1,2-ethanedithiol (EDT) as a hole transport layer (HTL) has limitations, such as energy level discrepancies, requisite oxidation, and intricate multilayer assembly. Organic p-type materials, lauded for their superior attributes and synthetic versatility, are now stepping forward as viable substitutes for conventional EDT HTLs. In this work, we introduced an organic HTL derived from indolo[3,2-b]carbazole, named ZL004, leading to a marked improvement in carrier generation and collection, facilitated by the optimized band alignment and enhanced interfacial charge dynamics. The ZL004-based PDs exhibit a photoresponsivity of 0.45 A/W, a noise current of 1.8 × 10-11 A Hz-0.5, a specific detectivity of 4.6 × 109 Jones, and an expansive linear dynamic range of 107 dB─surpassing EDT-based devices across the board, demonstrating the extraordinary property of organic p-type materials for CQD-based PDs.

11.
Chem Commun (Camb) ; 60(40): 5294-5297, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38659410

RESUMO

We developed a triazatruxene-based hole transport material (HTM), 3Ka-DBT-3Ka, aiming to enhance band alignment and augment charge generation and collection in devices, as an alternative for 1,2-ethanedithiol (EDT). The PbS CQD solar cells employing 3Ka-DBT-3Ka as the HTM achieve a peak efficiency of 11.4%, surpassing devices employing the conventional PbS-EDT HTM (8.9%).

12.
Adv Sci (Weinh) ; : e2402756, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38696647

RESUMO

Colloidal quantum dots (CQDs) are promising optoelectronic materials for solution-processed thin film optoelectronic devices. However, the large surface area with abundant surface defects of CQDs and trap-assisted non-radiative recombination losses at the interface between CQDs and charge-transport layer limit their optoelectronic performance. To address this issue, an interface heterojunction strategy is proposed to protect the CQDs interface by incorporating a thin layer of polyethyleneimine (PEIE) to suppress trap-assisted non-radiative recombination losses. This thin layer not only acts as a protective barrier but also modulates carrier recombination and extraction dynamics by forming heterojunctions at the buried interface between CQDs and charge-transport layer, thereby enhancing the interface charge extraction efficiency. This enhancement is demonstrated by the shortened lifetime of carrier extraction from 0.72 to 0.46 ps. As a result, the resultant PbS CQD solar cells achieve a power-conversion-efficiency (PCE) of 13.4% compared to 12.2% without the heterojunction.

13.
Phys Chem Chem Phys ; 15(40): 17452-9, 2013 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-24026110

RESUMO

Three new phenothiazine dyes were designed and synthesized, utilizing different acceptor groups. Upon application to TiO2-based solar cells, the effects of different acceptors on the photophysical and electrochemical properties of the dyes and the solar cell performance are detailed. The introduction of a pyridinium unit or 5-carboxy-1-hexyl-2,3,3-trimethyl-indolium unit into the molecular frame as the acceptor instead of cyano acrylic acid can effectively cause a red shift in the absorption spectra. Applied to DSSCs, the devices sensitized by CM502 with the pyridinium unit as the acceptor show the highest efficiency of 7.3%. The devices fabricated with dye CM501 with cyano acrylic acid as the acceptor exhibited the highest Voc while for the devices sensitized by the dye CM503 with 5-carboxy-1-hexyl-2,3,3-trimethyl-3H-indolium unit as the acceptor, the Voc value was the lowest, at 494 mV. The addition of TBP in the electrolyte can improve the performance of DSSCs fabricated using CM501 and CM502, with the Voc value greatly improved but the Jsc value slightly decreased. However, with the addition of TBP in the electrolyte, the efficiency of the cells sensitized by CM503 dropped significantly (from 4.9% to 1.0% when 0.1 M TBP was added).

14.
Phys Chem Chem Phys ; 15(36): 15146-52, 2013 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-23925069

RESUMO

In the present study, tetramethylammonium hydroquinone (HQ)/benzoquinone (BQ) were developed for use as a redox couple, with poly(3,4-ethylenedioxythiophene) (PEDOT) and multiwalled carbon nanotubes (MWNT) being proposed for use as counter electrode (CE) catalysts in dye-sensitized solar cells (DSSCs). Both metal-complex N719 and metal-free organic dye CM309 were employed to fabricate devices. For the devices sensitized by N719, when using PEDOT and MWNT CEs, power conversion efficiencies (PCE) of 5.2 and 4.9% were obtained, respectively, which were much higher than that of the device using the traditional Pt CE (4.7%) when HQ/BQ electrolyte was employed. However, with the HQ/BQ redox shuttle, the efficiency of the devices sensitized by N719 is much lower than that of the devices when the traditional I(-)/I3(-) based electrolyte and Pt CE were employed (7.9%). While for the CM309 sensitized solar cells, when the HQ/BQ redox shuttle was employed, PEDOT and MWNT performed much better than Pt, the DSSC using the PEDOT CE showed an efficiency of 6.2%, which was close to that of the DSSC using the traditional I(-)/I3(-) electrolyte and Pt CE (6.3%).


Assuntos
Benzoquinonas/química , Corantes/química , Fontes de Energia Elétrica , Hidroquinonas/química , Energia Solar , Eletrodos , Estrutura Molecular , Nanotubos de Carbono/química , Compostos Organometálicos/química , Oxirredução , Tamanho da Partícula , Propriedades de Superfície
15.
J Cutan Pathol ; 40(11): 945-9, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24102654

RESUMO

BACKGROUND: Benign lymphangioendothelioma represents a rare lymphatic vascular proliferation characterized by proliferation of irregular and thin-walled vessels dissecting amongst dermal collagen. Immunohistochemical analysis has been lacking in most previously reported cases. METHODS: Herein, we report the clinical and histopathologic characteristics of four cases of benign lymphangioendothelioma. Immunohistochemical study was completed for all lesions. RESULTS: All lesions presented as large, red to brown patches or plaques. Three lesions were located on the thigh and one lesion was located on the neck. Histopathologically, all lesions showed proliferation of anastomotic or retiform thin-walled vessels with a single layer of endothelial cells that dissect the dermis. D2-40 and Prox1 immunostains were positive and Wilms tumor 1 (WT-1) immunostain was negative in all cases. CONCLUSION: Benign lymphangioendothelioma represents a lymphatic vascular proliferation. A lack of expression of WT-1 suggests it represents a lymphatic vascular malformation.


Assuntos
Biomarcadores Tumorais/análise , Linfangioma/patologia , Neoplasias Cutâneas/patologia , Adulto , Criança , Feminino , Humanos , Imuno-Histoquímica , Linfangioma/metabolismo , Masculino , Pescoço/patologia , Neoplasias Cutâneas/metabolismo , Coxa da Perna/patologia , Adulto Jovem
16.
Chemistry ; 18(50): 16196-202, 2012 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-23081757

RESUMO

New hemicyanine dyes (CM101, CM102, CM103, and CM104) in which tetrahydroquinoline derivatives are used as electron donors and N-(carboxymethyl)-pyridinium is used as an electron acceptor and anchoring group were designed and synthesized for dye-sensitized solar cells (DSSCs). Compared with corresponding dyes that have cyanoacetic acid as the acceptor, N-(carboxymethyl)-pyridinium has a stronger electron-withdrawing ability, which causes the absorption maximum of dyes to be redshifted. The photovoltaic performance of the DSSCs based on dyes CM101-CM104 markedly depends on the molecular structures of the dyes in terms of the n-hexyl chains and methoxyl. The device sensitized by dye CM104 achieved the best conversion efficiency of 7.0% (J(sc) = 13.4 mA cm(-2), V(oc) = 704 mV, FF = 74.8%) under AM 1.5 irradiation (100 mW cm(-2)). In contrast, the device sensitized by reference dye CMR104 with the same donor but the cyanoacetic acid as the acceptor gave an efficiency of 3.4% (J(sc) =6.2 mA cm(-2), V(oc) = 730 mV, FF = 74.8%). Under the same conditions, the cell fabricated with N719 sensitized porous TiO(2) exhibited an efficiency of 7.9% (J(sc) = 15.4 mA cm(-2) , V(oc) = 723 mV, FF = 72.3%). The dyes CM101-CM104 show a broader spectral response compared with the reference dyes CMR101-CMR104 and have high IPCE exceeding 90% from 450 to 580 nm. Considering the reflection of sunlight, the photoelectric conversion efficiency could be almost 100% during this region.

17.
Phys Chem Chem Phys ; 14(33): 11592-5, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-22828680

RESUMO

A new type of electrolyte with a sulfide/polysulfide redox couple and I(-) was prepared as a solvent-free ionic liquid for application in dye-sensitized solar cells, reaching efficiencies of 5.2-6.4% under AM 1.5G, 100 mW cm(-2) light illumination, and 6.6% efficiency was obtained under 0.1 sun irradiation.

18.
Phys Chem Chem Phys ; 14(8): 2816-31, 2012 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-22258566

RESUMO

Time-resolved emission and absorption spectroscopy are used to study the photoinduced dynamics of forward and back electron transfer processes taking place between a recently synthesized series of donor-(π-spacer)-acceptor organic dyes and semiconductor films. Results are obtained for vertically oriented titania nanotube arrays (inner diameters 36 nm and 70 nm), standard titania nanoparticles (25 nm diameter) and, as a reference, alumina nanoparticle (13 nm diameter) films. The studied dyes contain a triphenylamine group as an electron donor, cyanoacrylic acid part as an electron acceptor, and differ by the substituents in a spacer group that causes a shift of its absorption spectra. Despite a red-shift of the dye absorption band resulting in an improved response to the solar spectrum, smaller electron injection rates and smaller extinction coefficients result in reduced dye sensitized solar cell (DSSC) conversion efficiencies. For the most efficient dye, TPC1, electron injection from the hot locally excited state to titania on a time scale of about 100 fs is suggested, while from the relaxed charge transfer state it proceeds in a non-exponential way with time constants from 1 ps to 50 ps. Our results imply that the latter process involves the trap states below the conduction band edge (or the sub-bandgap tail of the acceptor states), localized close to the dye radical cation, and is accompanied by fast electron recombination to the parent dye's ground state. This process should limit the efficiency of DSSCs made using these types of organic dyes. The residual, slower recombination can be described by a stretched exponential decay with a characteristic time of 0.5 µs and a dispersion parameter of 0.33. Both the electron injection and back electron transfer dynamics are similar in titania nanoparticles and nanotubes. Variations between the two film types are only found in the time resolved emission transients, which are explained in terms of the difference in local electric fields affecting the position of the emission bands.

19.
Angew Chem Int Ed Engl ; 51(39): 9896-9, 2012 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-22952034

RESUMO

A hybrid electrolyte involving tetramethylammonium (TMA) hydroquinone/benzoquinone redox couple is formulated. This electrolyte is more transparent than the traditional I(-)/I(3)(-) electrolyte and has negligible absorption in the visible region. Dye-sensitized solar cells using the hybrid electrolyte show higher light-to-electricity conversion efficiency. FTO=fluorine-doped tin oxide.


Assuntos
Benzoquinonas/química , Corantes/química , Fontes de Energia Elétrica , Hidroquinonas/química , Energia Solar , Eletricidade , Eletrólitos/química , Oxirredução , Compostos de Estanho/química
20.
An Bras Dermatol ; 97(4): 498-500, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35691739

RESUMO

Balamuthia mandrillaris infection is a rare infectious disease around the world, with high rates of morbidity and mortality. Its early and correct diagnosis is a big challenge for us, and without it the delay in starting effective treatment can lead to the development of encephalitis. This is a report of a case of Balamuthia mandrillaris infection in a Chinese boy, with red plaques on the nasal dorsum as the first presentation, who finally developed into fatal encephalitis. The authors have reviewed the related literature and share the special skin features in order to favor the early diagnosis of the disease and increase the chances of survival.


Assuntos
Amebíase , Balamuthia mandrillaris , Encefalite , Amebíase/diagnóstico , Encéfalo , Encefalite/diagnóstico , Humanos , Masculino , Nariz , Pele
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA