Perovskite solar cells are amongst the most exciting photovoltaic systems as they combine low recombination losses, ease of fabrication and high spectral tunability. The Achilles heel of this technology is the device stability due to the ionic nature of the perovskite crystal, rendering it highly hygroscopic, and the extensive diffusion of ions especially at elevated temperatures. Herein, we demonstrate the application of a simple solution-processed perfluorinated self-assembled monolayer (p-SAM) that not only passivates the perovskite surface but also drastically improves the stability of the perovskite absorber and in turn the solar cell under elevated temperature or humid conditions. p-i-ntype perovskite devices employing these SAMs exhibited power conversion efficiencies surpassing 21%. Notably, the best performing devices are stable under standardized maximum-power point (MPP) operation at 85°C in inert atmosphere (ISOS-L-2) for more than 250 h, and exhibit superior humidity resilience, maintaining ~95% device performance even if stored in humid air in the ambient over months (~3000h, ISOS-D-1). Our work, therefore, demonstrates a novel strategy towards efficient and stable perovskite solar cells with easily deposited functional interlayers. Supporting Information.Experimental Methods, Supplementary Notes and Calculations, Details on Simulation, XRD, UV-Vis, XPS, FTIR, KP data, PL vs time, SPV measurements as well as additional experimental methods.

Quantitative blood cultures were obtained from 42 patients with acute Yersinia pestis infection to determine whether the concentration of bacteria in blood influenced the clinical severity and outcome of illness. In 17 bacteremic patients, colony counts in blood cultures ranged from less than 10 to 4 X 10(7)/ml. Three of five patients with colony counts of greater than 10(2)/ml died, and two patients survived episodes of hypotension. Results from plasma limulus tests were positive at the time of admission in three of 10 patients tested, and these three patients had bacteremia with colony counts of greater than 10(2)/ml. Meningitis developed in three patients and pneumonia in two patients; these five patients a-l had buboes in the axillary region. Endotoxin was detected with the limulus test in the cerebrospinal fluid in the three patients with meningitis. Ten patients randomly assigned to receive streptomycin or trimethoprim-sulfamethoxazole survived. Those treated with streptomycin had a shorter median duration of fever and a lower incidence of complications than did the patients treated with trimethoprim-sulfamethoxazole.

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A dual criterion of equivalent linearization method is suggested. The mean-square responses of Duffing, Van der Pol and Lutes-Sarkani oscillators subjected to random excitation are considered. The obtained results are compared with the numerical calculations of original systems and approximate solutions obtained by three different methods including the conventional linearization technique, energy method and regulation linearization method. The results show that in those nonlinear systems the accuracy of the mean-square response is significantly improved by the proposed criterion.

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Antimicrobial-resistant typhoid fever in Saigon was studied by examining in vitro antimicrobial susceptibilities ofSalmonella typhi strains and conducting a randomized clinical trial of ampicillin and trimethoprim-sulfamethoxazole (TMP-SMZ). Isolates of S. typhi were obtained from blood or stool cultures of 90 patients. Of 87 isolates tested for antimicrobial susceptibility, 65 (75%) were resistant (R) to chloramphenicol, streptomycin, sulfonamide, and tetracycline, and 22 (25%) were susceptible (S). The drug resistance was transferable to Escherichia coli and was found in 11 different Vi-phage types. All isolates were susceptible to ampicillin and to TMP-SMZ. Agar dilution studies of TMP and SMZ showed synergistic inhibition of growth in all 18 S isolates and in 12 of 48 R isolates tested. The clinical trial of ampicillin and TMP-SMZ showed that both drugs were equally effective. Treatment failure with both drugs was more frequent in patients with S isolates than in patients with R isolates. Therefore, in an area where antimicrobial-resistant typhoid fever exists, patients with R isolates should receive either ampicillin or TMP-SMZ, but patients with S isolates should be treated with chloramphenicol.

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Liquid–liquid phase transition in liquid Al2O3·2SiO2 (AS2) has been studied at 4200 K in a model containing 3025 particles under periodic boundary conditions with Born–Mayer type pair potentials via molecular dynamics (MD) simulation. Structure and dynamics of models at densities ranging from 2.60 to 4.20 g cm−3 at a temperature of 4200 K have been analysed in detail through the partial radial distribution functions (PRDF), coordination number distribution, bond-angle distribution, interatomic distances and diffusion constant. We found clear evidence of transition from a tetrahedral to an octahedral network structure in the model upon compression, like that observed in simple oxide systems. Moreover, the transition is accompanied by an anomalous diffusion of components in the system.