Effect of size on the thermal noise and acoustic response of viscous-driven microbeams.

A study is presented of the thermal-mechanical noise and response to sound of microphones that are designed to be driven by the viscous forces in air rather than by sound pressure. Virtually all existing microphone designs are intended to respond to sound pressure. The structures examined here consist of thin, micro-scale, cantilever beams. The viscous forces that drive the beams are proportional to the relative velocity between the beams and fluid medium. The beams' movement in response to sound is similar to that of the air in a plane acoustic wave. The thermal-mechanical noise of these beams is found to be a very weak function of their width and length; the size of the sensing structure does not appear to significantly affect the performance. This differs from the well-known importance of the size of a pressure-sensing microphone in determining the pressure-referred noise floor. Creating microphones that sense fluid motion rather than pressure could enable a significant reduction in the size of the sensing element. Calculated results are revealed to be in excellent agreement with the measured pressure-referred thermal noise.

Bilateral central serous retinal detachment in a patient with nephrotic syndrome: a case report.

BACKGROUND: The aim of this report is to highlight the importance of considering nephrotic syndrome as a potential underlying cause of bilateral central serous retinal detachment in a patient with systemic lupus erythematosus and to underscore the significance of a comprehensive systemic workup in these patients. CASE PRESENTATION: A 19-year-old Iranian female patient with history of systemic lupus erythematosus presented with progressive vision loss and bilateral macular elevation. Ophthalmic examination revealed periorbital edema, chemosis, and subretinal fluid at the macula of both eyes. Optical coherence tomography confirmed the existence of subretinal fluid and serous detachment located at the macula of both eyes. On fluorescein angiography, there were no signs of subretinal leakage such as smoke stack sign or expansile dot in late phases. Laboratory tests detected hypoalbuminemia and significant proteinuria, leading to the diagnosis of nephrotic syndrome. Treatment with prednisolone and albumin infusion resulted in improved visual acuity and resolution of subretinal fluid. CONCLUSION: Nephrotic syndrome can be a rare underlying cause of bilateral central serous retinal detachment, and its association with systemic lupus erythematosus should be considered. Hypoalbuminemia in nephrotic syndrome alters fluid dynamics in the retina, contributing to bilateral central serous retinal detachment. Early recognition and management of nephrotic syndrome are essential for vision recovery and preventing long-term complications.

Mechanism and antibacterial synergies of poly(Dabco-BBAC) nanoparticles against multi-drug resistant Pseudomonas aeruginosa isolates from human burns.

Multi-drug resistant bacteria are a major problem in the treatment of infectious diseases, such as pneumonia, meningitis, or even coronavirus disease 2019 (COVID-19). Cationic nanopolymers are a new type of antimicrobial agent with high efficiency. We synthesized and characterized cationic polymer based on 1,4-diazabicyclo [2.2.2] octane (DABCO) and Bis (bromoacetyl)cystamine (BBAC), named poly (DABCO-BBAC) nanoparticles(NPs), and produced 150 nm diameter NPs. The antibacterial activity of poly (DABCO-BBAC) against eight multi drug resistant (MDR) Pseudomonas aeruginosa isolates from human burns, its possible synergistic effect with gentamicin, and the mechanism of action were examined. Poly(DABCO-BBAC) could effectively inhibit and kill bacterial strains at a very low concentration calculated by minimum inhibitory concentration (MIC) assay. Nevertheless, its synergism index with gentamicin showed an indifferent effect. Moreover, transmission electron microscopy and lipid peroxidation assays showed that poly (DABCO-BBAC) distorted and damaged the bacterial cell wall. These results suggest that the poly (DABCO-BBAC) could be an effective antibacterial agent for MDR clinical pathogens.

Role of Different Types of Contact Lenses in Epithelial Thickness.

OBJECTIVE: To evaluate the potential role of different types of contact lenses, such as soft (SCL), hard (HCL), and mini scleral (SCCL), in corneal epithelial thickness with anterior segment optical coherence tomography (AS-OCT). METHODS: In this cross-sectional study, patients who used contact lens at recent 6 months were recruited consecutively from September 2019 to October 2019, and the epithelial thicknesses of the cornea were obtained by AS-OCT and compared with control subjects who did not use contact lens. RESULTS: In total, 184 eyes (115 subjects) were included; of them, 75 eyes were keratoconic (KCN) and 109 eyes were nonkeratoconic (non-KCN). Twenty eyes in KCN and 79 eyes of non-KCN group had no history of contact lens use and were included for comparison with KCN and non-KCN contact lens users, respectively. Mean duration of contact lens wearing was 75.63±50.42 months. The epithelial thickness of non-KCN SCL group was thinner than that of non-KCN control subjects all over the cornea, whereas the epithelium of non-KCN HCL was thinner at central site as well as nasal and temporal paracentral and midperipheral areas. Epithelial thickness of the KCN HCL group was not different from the KCN control subjects in all sectors. The KCN SCCL group had thinner epithelium at nearly all peripheral sectors as well as inferior, inferotemporal, inferonasal, and nasal midperipheral sectors compared with KCN control subjects. CONCLUSION: The corneal epithelium was thinner at the peripheral zones in KCN SCCL users; at both peripheral and central zones in non-KCN SCL users and in central zones in non-KCN HCL users.

The role of miRNA-377 as a tumor suppressor in lung cancer by negative regulation of genes belonging to ErbB signaling pathway.

BACKGROUND: The ErbB signaling pathway plays important role in the pathogenesis of lung cancer. We explored the role of miRNA-377 as a tumor suppressor in NSCLC through silencing of some genes in the ErbB pathway. METHODS AND RESULTS: The targeting effect of miRNA-377 on EGFR, MAPK1, ABL2, and PAK2 was evaluated. The expression levels of these genes and miRNA-377 were surveyed in NSCLC and normal human tissues, Calu-6, and A549 cells. Real-time PCR was used to figure out whether miRNA-377 could decrease the target genes mRNAs in transfected lung cancer cell lines. The effects of miRNA-377 on apoptosis cell and proliferation were analyzed. We showed that miRNA-377 targets EGFR, MAPK1, and PAK2 mRNAs in in-silico and luciferase reporter assay. The expression of miRNA-377 was significantly downregulated in human NSCLC tissues, Calu-6 and A549 cells compared to their controls. We observed a negative correlation between EGFR, MAPK1, PAK2, and miRNA-377 expression in human NSCLC tissues. A significant reduction in EGFR, MAPK1, and PAK2 mRNA levels was detected, following miRNA-377 transfection in Calu-6 and A549 cells. The higher levels of miRNA-377 in Calu-6, and A549 cells induced apoptosis and reduced proliferation, significantly. CONCLUSIONS: All these data reveal that miRNA-377 functions as a tumor suppressor in NSCLC and may serve as a potential therapeutic target for the treatment of NSCLC.

Orbital Dirofilariasis Masquerading As Orbital Rhabdomyosarcoma.

Purpose: To report a 12-year-old patient with a rapid growing orbital mass and imaging findings suggestive of rhabdomyosarcoma that was found to be dirofilariasis after mass resection. Case Report: We describe a 12-year-old patient with a rapid growing orbital mass involving medial part of orbit and medial rectus muscle and imaging findings suggestive of rhabdomyosarcoma. Histopathologic examination showed the mass to be composed of granulomatous inflammation and the thread-like object to be Dirofilaria repens. The patient was well post-operation without morbidity. In this paper, we describe distinct clinical features and imaging findings of this interesting case. Conclusion: Deep orbital lesions due to dirofilariasis, as in our case, is extremely rare. It is important to add dirofilariasis to the differential diagnosis of orbital mass lesions. Attention to the imaging clues, as provided in this report, can be helpful.

p53 codon 72 polymorphism association with head and neck squamous cell carcinoma.

UNLABELLED: p53 tumoral suppressor gene harbors a functional polymorphism which codes either arginine (Arg) or proline (Pro) in the protein p53 of codon 72. Such polymorphism has been associated with the development or prognosis of head and neck squamous cell carcinoma (HNSCC). AIM: we assessed codon 72 p53 allelic frequencies and genotypes in HNSCC Iranian patients. STUDY DESIGN: Case Study. MATERIALS AND METHODS: a total of 132 HNSCC patients and 123 healthy controls were genotyped. DNA source was from mononuclear cells of the peripheral blood. DNA amplification was done by means of the allele-specific polymerase chain reaction. RESULTS: genotypes and allele distribution were not significantly different between patients and controls. Moreover, no statistically significant association was found between the 72 and p53 codon tumor location, gender or age at the time of diagnosis. However, the Pro/Pro genotype was significantly increase in stage IV patients (30.8%) when compared to stages I-III of the disease (11.1%) (p=0.03), and a significantly higher percentage of patients with the Pro allele had and a risk increase in stage IV disease (OR=2.2, 95% CI=1.2-4.2, p=0.01). CONCLUSION: data revealed that the p53 polymorphism do not impact the risk of HNSCC in Iranians, nonetheless, it can affect tumor progression to a higher tumor stage.

Associação entre carcinoma espinocelular de cabeça e pescoço e polimorfismo no p53 (códon 72) / P53 codon 72 polymorphism association with head and neck squamous cell carcinoma

P53 tumoral suppressor gene harbors a functional polymorphism which codes either arginine (Arg) or proline (Pro) in the protein p53 of codon 72. Such polymorphism has been associated with the development or prognosis of head and neck squamous cell carcinoma (HNSCC). AIM: we assessed codon 72 p53 allelic frequencies and genotypes in HNSCC Iranian patients. STUDY DESIGN: Case Study. MATERIALS AND METHODS: a total of 132 HNSCC patients and 123 healthy controls were genotyped. DNA source was from mononuclear cells of the peripheral blood. DNA amplification was done by means of the allele-specific polymerase chain reaction. RESULTS: genotypes and allele distribution were not significantly different between patients and controls. Moreover, no statistically significant association was found between the 72 and p53 codon tumor location, gender or age at the time of diagnosis. However, the Pro/Pro genotype was significantly increase in stage IV patients (30.8 percent) when compared to stages I-III of the disease (11.1 percent) (p=0.03), and a significantly higher percentage of patients with the Pro allele had and a risk increase in stage IV disease (OR=2.2, 95 percent CI=1.2-4.2, p=0.01). CONCLUSION: data revealed that the p53 polymorphism do not impact the risk of HNSCC in Iranians, nonetheless, it can affect tumor progression to a higher tumor stage.

O gene supressor tumoral p53 abriga um polimorfismo funcional que codifica ou arginina (Arg) ou prolina (Pro) no códon 72 da proteína p53. Este polimorfismo tem sido considerado associado com o desenvolvimento e prognóstico do carcinoma espinocelular de cabeça e pescoço (CECP). OBJETIVO: Foram avaliados genótipo e freqüências alélicas do códon 72 do p53 em pacientes iranianos com CECP. TIPO DE ESTUDO: Estudo de Caso. MATERIAIS E MÉTODOS: Um total de 132 pacientes com CECP e 123 controles saudáveis foram genotipados. A fonte de DNA foi composta de células mononucleares do sangue periférico. A amplificação do DNA foi realizada através da reação em cadeia da polimerase específica para alelos. RESULTADOS: A distribuição dos alelos e genótipos não foi significativamente diferente entre os pacientes e controles. Além disso, nenhuma associação estatisticamente significativa foi encontrada entre o polimorfismo do códon 72 do p53 e localização, sexo ou idade no momento do diagnóstico. No entanto, o genótipo Pro/Pro estava significativamente aumentado em pacientes no estágio IV (30,8 por cento) quando comparado ao estágio I-III da doença (11,1 por cento) (p=0,03), e um número significativamente maior de doentes com o alelo Pro teve um aumento no risco de desenvolver doença no estágio IV (OR=2,2, IC= 95 por cento =1.2-4.2, p=0,01). CONCLUSÃO: Os dados revelaram que o polimorfismo do p53 não afeta o risco de CECP em iranianos; porém, pode afetar a progressão para um estágio superior tumor.