Self-Powered Chemical Sensing Driven by Graphene-Based Photovoltaic Heterojunctions with Chemically Tunable Built-In Potentials.

Ultralow power chemical sensing is essential toward realizing the Internet of Things. However, electrically driven sensors must consume power to generate an electrical readout. Here, a different class of self-powered chemical sensing platform based on unconventional photovoltaic heterojunctions consisting of a top graphene (Gr) layer in contact with underlying photoactive semiconductors including bulk silicon and layered transition metal dichalcogenides is proposed. Owing to the chemically tunable electrochemical potential of Gr, the built-in potential at the junction is effectively modulated by absorbed gas molecules in a predictable manner depending on their redox characteristics. Such ability distinctive from bulk photovoltaic counterparts enables photovoltaic-driven chemical sensing without electric power consumption. Furthermore, it is demonstrated that the hydrogen (H2 ) sensing properties are independent of the light intensity, but sensitive to the gas concentration down to the 1 ppm level at room temperature. These results present an innovative strategy to realize extremely energy-efficient sensors, providing an important advancement for future ubiquitous sensing.

Effect of transcranial direct current stimulation on visual perception function and performance capability of activities of daily living in stroke patients.

[Purpose] The purpose of this study was to examine the effects of transcranial direct current stimulation (tDCS) on visual perception and performance of activities of daily living in patients with stroke. [Subjects and Methods] Thirty subjects were assigned equally to a tDCS plus traditional occupational therapy group (experimental group) and a traditional occupational therapy group (control group). The intervention was implemented five times per week, 30 minutes each, for six weeks. In order to assess visual perception function before and after the intervention, the motor-free visual perception test (MVPT) was conducted, and in order to compare the performance of activities of daily living, the Functional Independence Measure scale was employed. [Results] According to the results, both groups improved in visual perception function and in performance of activities of daily living. Although there was no significant difference between the two groups, the experimental group exhibited higher scores. [Conclusion] In conclusion, the application of tDCS for the rehabilitation of patients with stroke may positively affect their visual perception and ability to perform activities of daily living.

Simultaneous occurrence of papulonecrotic tuberculid and erythema induratum in a patient with pulmonary tuberculosis.

Although papulonecrotic tuberculid is an uncommon cutaneous manifestation of tuberculosis (TB) associated with Mycobacterium tuberculosis infection, the simultaneous occurrence of papulonecrotic tuberculid and erythema induratum is even rarer. Papulonecrotic tuberculid occurs predominantly in young adults and is characterized by eruptions of necrotizing papules that heal with varioliform scars. Histopathologic findings include wedge-shaped necrosis of the dermis, poorly formed granulomatous infiltration, and vasculitis. Stainings and culture for acid-fast bacilli from skin biopsies are usually negative for M. tuberculosis, although the eruptions resolve with antitubercular therapy. Few patients with papulonecrotic tuberculid, especially with concurrent occurrence of erythema induratum, have been reported in the English literature. Here we report a case of a 12-year-old girl with simultaneous occurrence of papulonecrotic tuberculid and erythema induratum accompanying pulmonary TB.

Direct CVD Growth of Transferable 3D Graphene for Sensitive and Flexible SERS Sensor.

Three-dimensional (3D) graphene (Gr) has been successfully grown on a patterned sapphire substrate (PSS) with very low mismatch between Gr and the sapphire nanostructure through metal-catalyst-assisted chemical vapor deposition (CVD). However, the transfer of the 3D Gr film without compromising the structural integrity of Gr is challenging because of the low etching rate of PSS. For easy and high-quality transfer of 3D Gr, we propose to coat a transfer-support layer (TSL) on PSS before direct CVD growth of 3D Gr. The TSL is directly deposited on PSS by atomic layer deposition without causing any structural changes in the substrate, as verified through atomic force microscopy (AFM). Few-layer 3D Gr is conformally produced along the surface of the TSL/PSS and successfully transferred onto a flexible substrate through wet-etching transfer, as confirmed by scanning electron microscopy, AFM, and Raman spectroscopy studies. We also present the fabrication of a sensitive and flexible surface-enhanced Raman scattering sensor based on 3D Gr on PMMA with high detection performance for low concentrations of R6G (10-9 M). The proposed transfer method with TSL is expected to broaden the use of 3D graphene in next-generation device applications.

Synthesis and Characterization of Tungsten Amide Complexes for the Deposition of Tungsten Disulfide Thin Films.

To substitute corrosive halogen ligands, we designed and synthesized novel tungsten complexes containing amido ligands, W(DMEDA)3 (1) and W(DEEDA)3 (2) (DMEDA = N,N'-dimethylethylenediamido; DEEDA = N,N'-diethylethylenediamido). Complexes 1 and 2 were characterized by 1H NMR, 13C NMR, FT-IR, and elemental analysis. The pseudo-octahedral molecular structure of 1 was confirmed by single-crystal X-ray crystallography. The thermal properties of 1 and 2 were analyzed by thermogravimetric analysis (TGA), which confirmed that the precursors were volatile and exhibited adequate thermal stability. Additionally, the WS2 deposition test was performed using 1 in thermal chemical vapor deposition (thermal CVD). Further analysis of the surface of the thin films was conducted using Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS).

Narrowband UVB treatment of progressive macular hypomelanosis.

BACKGROUND: Little information is available on effective treatments for progressive macular hypomelanosis (PMH). To our knowledge, only one case of narrowband ultraviolet B (NB-UVB) therapy as an efficient treatment for patients with PMH has been reported in the recent literature. OBJECTIVE: We aimed to investigate the clinical features of PMH in Koreans and to determine the therapeutic efficacy of NB-UVB therapy in the management of PMH. METHODS: We performed an uncontrolled prospective study designed to evaluate the usefulness of NB-UVB therapy in PMH. A total of 23 patients with PMH were enrolled in the study. Of these, 17 patients underwent treatment with NB-UVB therapy once or twice weekly and were eligible for analysis. The remaining 6 patients were lost to follow-up before completion of the treatment. Repigmentation was evaluated by two dermatologists using photographic documentation. RESULTS: In our trial, NB-UVB therapy was used successfully in 9 of 16 patients (56.2%), who showed more than 90% repigmentation. We found that 13 of 16 patients (81.3%) experienced at least 50% repigmentation. The repigmented sites showed an excellent color match. No signs of recurrence have been detected in 11 of these 16 patients (68.7%) up to the present time (13.2 ± 8.2 months of follow-up). LIMITATIONS: Our study includes a small number of subjects examined, and it was an uncontrolled and non-double-blind study. CONCLUSIONS: The findings of this study suggest that NB-UVB therapy is an effective and safe method for use in the treatment of PMH.

Multilevel Anti-Counterfeiting Based on Covert Structural Features Embedded in Femtosecond-Laser-Treated Gold Nanocluster/Graphene Hybrid Layer.

The conventional nanoscale anti-counterfeiting scheme, exhibiting limited encoding capacity, faces growing challenges of being falsified with the advent of advanced high-resolution equipment. In this study, we propose a multilevel anti-counterfeiting device based on a femtosecond laser (fs-laser) treated plasmonic gold nanocluster/graphene (AuNC/Gr) hybrid structure integrated with a resonant cavity. The covert structural features encoded in random colored patterns, optical reflection spectra, and Raman spectra constitute three classes of anti-counterfeiting signatures, which originate from the AuNC-covered Gr, which initiates plasmonic and thermal couplings. The attendant inverted thermal distribution is presumed to confine the structural features to the AuNC-Gr interface while leaving no detectable traces on the surface of AuNC/Gr even under advanced high-resolution equipment. Therefore, the proposed approach achieves multilevel anti-counterfeiting accomplishing physically unclonable functions in the form of random colored patterns, reflection spectra, and Raman spectra. As the first report for realizing remarkable optical modulation (i.e., random colored patterns) without any surface trace or damage via fs-laser-AuNC/Gr interaction, our study also discloses the outstanding performance of Gr in fs-laser-induced optothermoplasmonic lithography on near-percolation metal films. Simultaneously, the demonstrated fs-laser-processed plasmonic hybrid structure in conjunction with a resonant cavity is anticipated to expand the encoding capabilities for nanoscale anti-counterfeiting while avoiding the risk of being imitated because of the covert structural features.

Bullae and sweat gland necrosis in the differential diagnosis for Vibrio vulnificus infection in an alcoholic patient.

Bullae and sweat gland necrosis remain rare cutaneous manifestation, and these conditions can be misdiagnosed as Vibrio vulnificus infections or other soft tissue infections because of their low index of suspicion. A 46-yr-old man with a history of continued alcohol consumption presented with erythematous and hemorrhagic bullous lesions on his left arm. The patient reported that after the ingestion of clams, he slept for 12 hr in a heavily intoxicated state. Then the skin lesions started as a reddish patch that subsequently became hemorrhagic bullae. V. vulnificus infection, cellulitis, and necrotizing fasciitis were considered in initial differential diagnosis. However, on the basis of sweat gland necrosis on histopathologic examinations and negative results on bacterial cultures, we made the diagnosis of bullae and sweat gland necrosis. Therefore, bullae and sweat gland necrosis should also be considered in chronic alcoholic patients who present with bullae and a previous history of unconsciousness.

Trichloroacetic acid matricectomy in the treatment of ingrowing toenails.

BACKGROUND: Ingrowing toenails can be treated with conservative therapy or surgery, but frequent relapse can be a problem in conservative therapy and surgical therapy without matricectomy. Thus, permanent nail ablation by partial matricectomy is now accepted as the treatment of choice. OBJECTIVE: To evaluate the efficacy and safety of trichloroacetic acid (TCA) matricectomy in the treatment of ingrowing nail. MATERIALS AND METHODS: Forty ingrowing toenail edges in 25 patients were enrolled. TCA matricectomy with 100% trichloroacetic acid after partial nail avulsion was performed. For a few weeks after surgery, postoperative complications such as pain, discharge, and infection were assessed. After a mean follow-up period of 22.9 months, recurrence rate and cosmetic outcomes were investigated to evaluate the effects of the surgery. RESULTS: The wounds almost always healed within 2 weeks without prolonged exudative discharge. Pain was mild and transient. A case of secondary infection occurred. Recurrence was found in only two nails of one patient, and the success rate was 95%, with good cosmetic results. CONCLUSION: TCA matricectomy showed a low recurrence rate with minimal side effects and was easy to perform in outpatient clinic. Therefore, it may be a good alternative treatment of ingrowing toenails.

Controlling electric potential to inhibit solid-electrolyte interphase formation on nanowire anodes for ultrafast lithium-ion batteries.

With increasing demand for high-capacity and rapidly rechargeable anodes, problems associated with unstable evolution of a solid-electrolyte interphase on the active anode surface become more detrimental. Here, we report the near fatigue-free, ultrafast, and high-power operations of lithium-ion battery anodes employing silicide nanowires anchored selectively to the inner surface of graphene-based micro-tubular conducting electrodes. This design electrically shields the electrolyte inside the electrode from an external potential load, eliminating the driving force that generates the solid-electrolyte interphase on the nanowire surface. Owing to this electric control, a solid-electrolyte interphase develops firmly on the outer surface of the graphene, while solid-electrolyte interphase-free nanowires enable fast electronic and ionic transport, as well as strain relaxation over 2000 cycles, with 84% capacity retention even at ultrafast cycling (>20C). Moreover, these anodes exhibit unprecedentedly high rate capabilities with capacity retention higher than 88% at 80C (vs. the capacity at 1C).

Reversible and Irreversible Responses of Defect-Engineered Graphene-Based Electrolyte-Gated pH Sensors.

We have studied the role of defects in electrolyte-gated graphene mesh (GM) field-effect transistors (FETs) by introducing engineered edge defects in graphene (Gr) channels. Compared with Gr-FETs, GM-FETs were characterized as having large increments of Dirac point shift (∼30-100 mV/pH) that even sometimes exceeded the Nernst limit (59 mV/pH) by means of electrostatic gating of H(+) ions. This feature was attributed to the defect-mediated chemisorptions of H(+) ions to the graphene edge, as supported by Raman measurements and observed cycling characteristics of the GM FETs. Although the H(+) ion binding to the defects increased the device response to pH change, this binding was found to be irreversible. However, the irreversible component showed relatively fast decay, almost disappearing after 5 cycles of exposure to solutions of decreasing pH value from 8.25 to 6.55. Similar behavior could be found in the Gr-FET, but the irreversible component of the response was much smaller. Finally, after complete passivation of the defects, both Gr-FETs and GM-FETs exhibited only reversible response to pH change, with similar magnitude in the range of 6-8 mV/pH.

Efficacy of 5% imiquimod cream on vulvar intraepithelial neoplasia in Korea: pilot study.

BACKGROUND: Various therapeutic options, including surgery, electrocautery, cryotherapy, 5-fluorouracil treatment, laser therapy, radiotherapy, photodynamic therapy, and interferon-α/γ injection, have been employed to treat vulvar intraepithelial neoplasia (VIN) with varying degrees of success. To truly cure VIN, human papillomavirus elimination is considered important. OBJECTIVE: To investigate the efficacy of 5% imiquimod cream used to treat VIN in Korean patients. METHODS: We performed a prospective, uncontrolled, observational study. Nine patients with histologically confirmed VIN applied 5% imiquimod cream to their vulvar lesions three to five times a week until a clinical response was apparent. All lesions were photo-documented, and therapeutic efficacy was assessed in terms of local adverse effects lesion number, size, and hyperpigmentation. RESULTS: The mean treatment duration was 30.2 months, and the median follow-up period after therapy completion was 30 months. Of the nine patients recruited, six (66.6%) experienced complete responses (CR) or partial responses (PR). Hyperpigmented patches in the VIN lesions were evident in five subjects (55.6%), and all experienced either CR or PR. Only three patients (33.3%) suffered from local adverse effects, which were relieved after temporary suspension of therapy, and better outcomes were attained ultimately. CONCLUSION: The imiquimod cream was more efficacious when used to treat VIN of the hyperpigmented type compared with lesions lacking pigmentation. The unifocal nature of a lesion and the development of local adverse effects are useful factors when imiquimod cream is prescribed. However, although the cream is convenient and effective, regional resistance may develop, and close follow-up is essential because VIN may become malignant.

Topical tacrolimus ointment for the treatment of lichen sclerosus, comparing genital and extragenital involvement.

Lichen sclerosus is a chronic inflammatory dermatosis presenting with significant sclerosis, atrophy and pruritus. The treatment for this condition remains unsatisfactory, with potent corticosteroids being the most effective therapy. In this study, we investigated the efficacy and safety of tacrolimus ointment in patients with genital and extragenital lichen sclerosus. Sixteen patients with active lichen sclerosus (10 with anogenital and six with extragenital localization) were treated with topical tacrolimus ointment twice daily. The therapeutic effects were evaluated according to 3 grades: complete response (>75% improvement), partial response (25-75% improvement), or no response (<25% improvement). Applications were continued until complete disappearance or stabilization of the cutaneous lesions. In addition, we conducted telephone surveys to determine the long-term treatment outcome and relapse rate. Objective response to therapy occurred in nine of 10 patients (90%) with anogenital and one of six patients (16.7%) with extragenital lesions. Out of 10 patients with anogenital lichen sclerosus, five showed more than 75% improvement. Complete, partial and no response were achieved in five (50%), four (40%) and one (10%) patient, respectively. During the follow-up period of a mean of 29.3 months, six of nine patients had a relapse of symptoms. However, most patients with extragenital involvement did not respond to tacrolimus, except one patient showing partial response. No significant adverse effects were observed. Topical tacrolimus ointment was a safe and effective treatment for genital lichen sclerosus and should be used for long-term duration to prevent relapse. However, it was not useful for patients with extragenital lichen sclerosus.

Lichen striatus occurring after allogenic peripheral blood stem cell transplantation in an adult with aplastic anemia.

Lichens striatus (LS) is an acquired, self-limiting inflammatory dermatosis that follows the lines of Blaschko. The etiology of the eruption is unknown, but several theories have been proposed with focus on environmental factors, viral infection, cutaneous injury, hypersensitivity, and genetic predisposition. We describe a 19-year-old woman who developed a unilateral linear eruption 17 months after allogenic peripheral blood stem cell transplantation. Histopathology revealed features, which were consistent with LS. To the best of our knowledge, our patient is the first case describing the appearance of LS occurring after allogenic stem cell transplantation. We speculate that this condition represents an unusual form of localized, chronic graft-versus-host disease.

Analysis of cardiovascular risk factors and metabolic syndrome in korean patients with psoriasis.

BACKGROUND: In previous studies, psoriasis has been reported to be associated with metabolic syndrome. OBJECTIVE: The purpose of this study was to evaluate risk factors for metabolic syndrome in psoriasis patients and to compare the prevalence of metabolic syndrome in psoriasis and control groups. METHODS: All patients (n=490) and controls (n=682) were investigated for cardiovascular risk factors, including central obesity, hypertension, fasting plasma glucose levels, and blood levels of triglycerides and high-density lipoprotein (HDL). RESULTS: We found no statistical association between psoriasis and the prevalence of metabolic syndrome when controlling for age and gender. Among individual components of metabolic syndrome, only increased triglyceride levels was significantly prevalent in patients psoriasis. The incidence of other factors such as central obesity, hypertension, fasting plasma glucose and HDL in the psoriasis group were similar to or lower than those in the control group. Although psoriasis patients with metabolic syndrome had severe and large plaque-type psoriasis, the association of metabolic syndrome with the severity or clinical subtype of psoriasis was not significant after adjusting for age and gender. CONCLUSION: Our results suggest that there is no close correlation between psoriasis and metabolic syndrome in Korean patients.

Delayed diagnosis of scrofuloderma misdiagnosed as a bacterial abscess.

An 82-year-old woman presented with a four-month history of an ulcerative plaque overlying her left neck. This lesion had developed as a subcutaneous nodule, gradually increased in size, and evolved into ulcers. Before visiting our Dermatology clinic, the patient had been diagnosed as having a bacterial abscess, but treatments with antibiotics were unsuccessful. The presence of a purulent discharge and prominent ulceration caused further confusion as bacterial abscess, and radiologic evaluation on computed tomography also led to the possibilities of secondary lesions from an abscess or malignancy. However, the characteristic appearance of her lesion allowed us to discern cutaneous tuberculosis, especially scrofuloderma. Based on clinical examinations, staining for acid-fast bacilli, and positive findings of polymerase chain reaction, a quick diagnosis of scrofuloderma was made. After that, she was treated successfully with anti-tuberculosis therapy and the ulcer healed. Our case highlights the problem of delayed diagnosis of scrofuloderma presenting as a bacterial abscess. In conclusion, having a high index of suspicion is needed to diagnose cutaneous tuberculosis correctly.

Vulval metastasis from squamous cell carcinoma of the cervix clinically presenting as lymphangioma circumscriptum.

Patients with cervical cancer may develop local recurrence or distant metastasis, and the rate of these events is increased in proportion to the clinical stage. Cutaneous metastasis of cervical cancer is very rare and only a few cases have been reported in Korean literature. It is common at the abdominal wall, vulva, and anterior chest wall and mainly presents as an asymptomatic dermal or subcutaneous nodule, ulcer or plaque. We herein report on an interesting case of vulval metastasis from squamous cell carcinoma of the cervix with an unusual clinical manifestation resembling lymphagioma circumscriptum.

Giant piloleiomyoma of the forehead.

Cutaneous piloleiomyomas are benign smooth muscle tumors arising from the arrector pili muscles. Piloleiomyomas appear as firm dermal papules of skin color or with a reddish to brown surface, and are commonly located on the extremities. Histologically, these lesions are composed of interlacing bundles of smooth muscle cells in the reticular dermis. Our case presented with an unusually large nodule on the forehead that was accompanied by intermittent pain. Histological analysis was compatible with piloleiomyoma and the lesion showed haphazardly arranged bundles of smooth muscle in the dermis. We describe herein an interesting case of a giant piloleiomyoma occurring on the forehead.