Broadband photonic crystal antireflection

Broadband antireflection layer have been fabricated by two dimensional (2D) photonic crystals (PCs) with tapered pillars on Si substrate. These PCs have been produced by interference lithography and reactive ion etching (RIE) techniques. The effect of depth and filling factor (FF) of the PCs on the reflectance magnitude and bandwidth has been investigated. The obtained reflectance was less than 1% in the broad spectral range from 400 to 2100 nm. Our numerically simulation shows the PC pillars slope has essential effect in the reduction of the reflection. However, our results show that the existence of RIE grasses in the PCs which are created in the RIE process have not been influenced in the performance of the antireflection layer which leads to simpler fabrication process

Exhaled nitric oxide is not a biomarker for idiopathic pulmonary arterial hypertension or for treatment efficacy

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) is a fatal illness. Despite many improvements in the treatment of these patients, there is no unique prognostic variable available to track these patients. The aim of this study was to evaluate the association between fractional exhaled nitric oxide (FeNO) levels, as a noninvasive biomarker, with disease severity and treatment outcome. METHODS: Thirty-six patients (29 women and 7 men, mean age 38.4 ± 11.3 years) with IPAH referred to the outpatient's clinic of Masih Daneshvari Hospital, Tehran, Iran, were enrolled into this pilot observational study. Echocardiography, six-minute walking test (6MWT), FeNO, brain natriuretic peptide (BNP) levels and the functional class of patients was assessed before patients started treatment. Assessments were repeated after three months. 30 healthy non-IPAH subjects were recruited as control subjects. RESULTS: There was no significant difference in FeNO levels at baseline between patients with IPAH and subjects in the control group. There was also no significant increase in FeNO levels during the three months of treatment and levels did not correlate with other disease measures. In contrast, other markers of disease severity were correlated with treatment effect over the three months. CONCLUSION: FeNO levels are a poor non-invasive measure of IPAH severity and of treatment response in patients in this pilot study

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42\ub74% vs 44\ub72%; absolute difference \u20131\ub769 [\u20139\ub758 to 6\ub711] p=0\ub767; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5\u20138] vs 6 [5\u20138] cm H2O; p=0\ub70011). ICU mortality was higher in MICs than in HICs (30\ub75% vs 19\ub79%; p=0\ub70004; adjusted effect 16\ub741% [95% CI 9\ub752\u201323\ub752]; p<0\ub70001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0\ub780 [95% CI 0\ub775\u20130\ub786]; p<0\ub70001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status. Funding: No funding

The diagnostic value of pleural fluid cytology and biopsy compared to surgical procedures in malignant pleural effusion

Background: As the accumulation of fluid in the pleural cavity is a common finding in patients with cancer, its diagnosis deserves careful consideration. The aim of this study was to compare the diagnostic value of pleural fluid cytology and biopsy to surgical biopsy in patients with suspected malignant pleural effusions.Materials and Methods: During a cross-sectional study, patients with exudative pleural effusion admitted to the Massih-Daneshvari hospital (Tehran) during an 18-month period were enrolled to determine the diagnostic value of pleural fluid cytology, closed needle biopsy and surgical biopsy in suspicious cases of malignant pleural effusion followed by a six-month final diagnosis.Results: A total of 318 patients (218 men and 100 women, aged 15-85) with a mean age of 59 years were recruited in this study. The sensitivity and negative predictive value of cytology for diagnosis of malignant pleural effusion were 32.4 and 65.6 for closed needle biopsy 65.9 and 63.2, and for surgical biopsy 87.8 and 80, respectively. Conclusion: A combination of pleural fluid cytology and biopsy has diagnostic value in 80 of cases of malignant pleural effusion and considering its simplicity, availability and low cost, these methods have acceptable diagnostic values compared to surgical biopsy

Effect of cyclic intravenous Iloprost therapy in patients with Idiopathic Pulmonary Artery Hypertension

Background: Prostacyclin have positive effects in improving the cardiopulmonary variables, signs and the hemodynamics of cases with a idiopathic pulmonary artery hypertension (IPAH).The objective of this study was to determine the benefits of intermittent intravenous Iloprost infusion on IPAH cases. Material and Methods: This longitudinal study was conducted on IPAH cases (no=20) at Massih Daneshvari Hospital (2011-2013), treated with cyclic intravenous Iloprost. The treatment consisted of a 6 hours/day Iloprost infusion for three consecutive days. Every 6 weeks the infusion was repeated again with a velocity of 0.5-2.0 ng/kg/min. Before, during and after the completion of functional class, six-minute walk test (6MWD), pulmonary artery pressure (PAP), right ventricular pressure (RVP), and plasma NT-ProBNP level were measured. Result: At follow-up, NYHA score, PAP, RVP, NT-ProBNP and PASP were significantly decreased (P<0.001), while the distance walked in 6MWD was significantly increased. Conclusion: Our results suggest that cyclic intravenous Iloprost might improve the NYHA score, PAP, RVP and can provide a protection against the development or worsening of PAH in patients with IPAH

Decreased neutrophil-mediated bacterial killing in COVID-19 patients

The coronavirus disease COVID-19 was first described in December 2019. The peripheral blood of COVID-19 patients have increased numbers of neutrophils which are important in controlling the bacterial infections observed in COVID-19. We sought to evaluate the cytotoxic capacity of neutrophils in COVID-19 patients. 34 confirmed COVID-19 patients (29 severe, five mild disease), and nine healthy controls were recruited from the Masih Daneshvari Hospital (Tehran, Iran) from March to May 2020. Polymorphonuclear (PMN) cells were isolated from whole blood and incubated with green fluorescent protein (GFP)-labelled methicillin-resistant Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA). Bacterial growth was determined by measuring the florescence of co-cultures of bacteria and neutrophils and reported as the lag time before exponential growth. The number of viable bacteria was determined after 70 hours as colony-forming units (CFU). The immunophenotype of tested cells was evaluated by flow cytometry. Isolated neutrophils have higher surface expression of CD16 and CD62L with negative markers for PMN-MDSC. Bacterial growth in the presence of SA (22 ± 0.9 versus 9.2 ± 0.5 h, P < .01) and PA (12.4 ± 0.6 versus 4.5 ± 0.22, P < .01) was significantly reduced in COVID-19 patients. After 70 h incubation of PMN with bacteria (SA and PA), CFUs were significant increased in COVID-19 patients SA (2.6 ± 0.09 × 108 CFU/mL-severe patients and 1.4 ± 0.06 × 108 CFU/mL-mild patients, P < .001) and PA (2.2 ± 0.09 × 109 CFU/mL-severe patients and 1.6 ± 0.03 × 109 CFU/mL-mild patients, P < .001). Gentamycin proliferation assays confirmed the presence of intracellular bacteria. Reduced bacterial killing by neutrophils from COVID-19 patients may be responsible for the high bacterial yield seen in these patients

Plasmapheresis reduces cytokine and immune cell levels in COVID-19 patients with acute respiratory distress syndrome (ARDS)

BACKGROUND: In December 2019, pneumonia associated with a novel coronavirus (COVID-19) was reported in Wuhan, China. Acute respiratory distress syndrome (ARDS) is the most frequently observed complication in COVID-19 patients with high mortality rates. OBJECTIVE OF STUDY: To observe the clinical effect of plasmapheresis on excessive inflammatory reaction and immune features in patients with severe COVID-19 at risk of ARDS. MATERIALS AND METHODS: In this single-center study, we included 15 confirmed cases of COVID-19 at Masih Daneshvari Hospital, in March 2020 in Tehran, Iran. COVID-19 cases were confirmed by RT-PCR and CT imaging according to WHO guidelines. Plasmapheresis was performed to alleviate cytokine-induced ARDS. The improvement in oxygen delivery (PaO2/FiO2), total number of T cells, liver enzymes, acute reaction proteins, TNF-α and IL-6 levels were evaluated. RESULTS: Inflammatory cytokine levels (TNF-α, IL-6), and acute phase reaction proteins including ferritin and CRP were high before plasmapheresis. After plasmapheresis, the levels of PaO2/FiO2, acute phase reactants, inflammatory mediators, liver enzymes and bilirubin were significantly reduced within a week (p < 0.05). In contrast, although the number of T helper cells decreased immediately after plasmapheresis, they rose to above baseline levels after 1 week. Nine out of fifteen patients on non-invasive positive-pressure ventilation (NIPPV) survived whilst the six patients undergoing invasive mechanical ventilation (IMV) died. CONCLUSION: Our data suggests that plasmapheresis improves systemic cytokine and immune responses in patients with severe COVID-19 who do not undergo IMV. Further controlled studies are required to explore the efficacy of plasmapheresis treatment in patients with COVID-19