Multispectral stealth multilayer etched film structure based on ultrathin silver.

Spontaneous infrared radiation dissipation is a critical factor in facilitating object cooling, which influences the thermal stability and stealth efficacy of infrared stealth devices. Furthermore, the compatibility between efficient visible, infrared, and radar stealth is challenging due to different camouflage principles in different bands. This Letter presents a five-layer etched film structure to achieve multispectral stealth, and the utilization of the high-quality ultrathin silver films enables highly efficient infrared selective emission. This etched film structure with few layers demonstrates potential applications in diverse domains, including multi-band anti-detection and multispectral manipulation.

A visible-near-infrared transparent miniaturized frequency-selective metasurface with a microwave transmission window.

In this work, we propose a meshed miniaturized frequency-selective metasurface (MMFSM), which is insensitive to the incidence microwave angle and has great optical imaging quality by extending the effective length of the aperture within the periodic unit and replacing large metal parts with different metallic meshes. Experimental results indicated that our MMFSM had an average normalized transmittance of 87.2% in the visible-near-infrared band, a passband loss of 1.446 dB, and an oblique incidence stabilization angle of 50° (the passband loss was less than 2.38 dB). These are excellent characteristics required for applications in the optics and communication fields.

High-Performance Transparent Ultrabroadband Electromagnetic Radiation Shielding from Microwave toward Terahertz.

In the era of fifth-generation networks and Internet-of-Things, the use of multiband electromagnetic radiation shielding is highly desirable for next-generation electronic devices. Herein, we report a systematic exploration of optoelectronic behaviors of ultrathin-silver-based shielding prototype (USP) film structures at the nanometer scale, unlocking the transparent ultrabroadband electromagnetic interference (EMI) shielding from microwave to terahertz frequencies. A theoretical model is proposed to optimize USP structures to achieve increased transparency, whereby optical antireflection resonances are introduced in dielectrics in conjunction with remarkable EMI shielding capability. USP can realize a state-of-the-art effective electromagnetic radiation shielding bandwidth with measured frequencies from 8 GHz up to 2 THz. Experimental results show that a basic USP (dAg = 10 nm) offers an average shielding efficiency of ∼27.5 dB from the X- to Ka-bands (8-40 GHz) and maintains a stable shielding performance of ∼22.6 dB across a broad range of 0.5-2 THz, with a measured optical transmittance of ∼95.2%. This extraordinary performance of ultrathin-silver-based film structures provides a new ultrabroadband EMI shielding paradigm for potential applications in next-generation electronics.

Should we initiate vasopressors earlier in patients with septic shock: A mini systemic review.

Septic shock treatment remains a major challenge for intensive care units, despite the recent prominent advances in both management and outcomes. Vasopressors serve as a cornerstone of septic shock therapy, but there is still controversy over the timing of administration. Specifically, it remains unclear whether vasopressors should be used early in the course of treatment. Here, we provide a systematic review of the literature on the timing of vasopressor administration. Research was systematically identified through PubMed, Embase and Cochrane searching according to PRISMA guidelines. Fourteen studies met the eligibility criteria and were included in the review. The pathophysiological basis for early vasopressor use was classified, with the exploration on indications for the early administration of mono-vasopressors or their combination with vasopressin or angiotensinII. We found that mortality was 28.1%-47.7% in the early vasopressors group, and 33.6%-54.5% in the control group. We also investigated the issue of vasopressor responsiveness. Furthermore, we acknowledged the subsequent challenge of administration of high-dose norepinephrine via peripheral veins with early vasopressor use. Based on the literature review, we propose a possible protocol for the early initiation of vasopressors in septic shock resuscitation.

ZmWRKY70 activates the expression of hypoxic responsive genes in maize and enhances tolerance to submergence in Arabidopsis.

Hypoxic stress due to submergence is a serious threat to the growth and development of maize. WRKY transcription factors are significant regulators of plant responses to various abiotic and biotic stresses. Nevertheless, their function and regulatory mechanisms in the resistance of maize to submergence stress remain unclear. Here we report the cloning of a maize WRKY transcription factor gene, ZmWRKY70, transcripts of which accumulate under submergence stress in maize seedlings. Subcellular localization analysis and yeast transcriptional activation assay indicated that ZmWRKY70 was localized in the nucleus and had transcriptional activation activity. Heterologous overexpression of ZmWRKY70 in Arabidopsis increased the tolerance of seeds and seedlings to submergence stress by upregulating the transcripts of several key genes involved in anaerobic respiration, such as group VII ethylene-responsive factor (ERFVII) (AtRAP2.2), alcohol dehydrogenase (AtADH1), pyruvate decarboxylase (AtPDC1/2), and sucrose synthase (AtSUS4), under submergence conditions. Moreover, the overexpression of ZmWRKY70 in maize mesophyll protoplasts enhanced the expression of ZmERFVII members (ZmERF148, ZmERF179, and ZmERF193), ZmADH1, ZmPDC2/3, and ZmSUS1. Yeast one-hybrid and dual-luciferase activity assays further confirmed that ZmWRKY70 enhanced the expression of ZmERF148 by binding to the W box motif located in the promoter region of ZmERF148. Together, these results indicate that ZmWRKY70 plays a significant role in tolerance of submergence stress. This work provides a theoretical basis, and suggests excellent genes, for biotechnological breeding to improve the tolerance of maize to submergence through the regulation of ZmWRKY genes.

Transparent and high-performance electromagnetic interference shielding composite film based on single-crystal graphene/hexagonal boron nitride heterostructure.

The multiple requirements of optical transmittance, high shielding effectiveness, and long-term stability bring considerable challenge to electromagnetic interference (EMI) shielding in the fields of visualization windows, transparent optoelectronic devices, and aerospace equipment. To this end, attempts were hereby made, and based on high-quality single crystal graphene (SCG)/hexagonal boron nitride (h-BN) heterostructure, transparent EMI shielding films with weak secondary reflection, nanoscale ultra-thin thickness and long-term stability were finally realized by a composite structure. In this novel structure, SCG was adopted as the absorption layer, while sliver nanowires (Ag NWs) film acted as the reflection layer. These two layers were placed on different sides of the quartz to form a cavity, which achieved the dual coupling effect, so that the electromagnetic wave was reflected multiple times to form more absorption loss. Among the absorption dominant shielding films, the composite structure in this work demonstrated stronger shielding effectiveness of 28.76 dB with a higher light transmittance of 80.6%. In addition, under the protection of the outermost h-BN layer, the decline range of the shielding performance of the shielding film was extensively reduced after 30 days of exposure to air and maintained long-term stability. Overall, this study provides an outstanding EMI shielding material with great potential for practical applications in electronic devices protection.

How to manage isolated tension non-surgical pneumoperitonium during bronchoscopy? A case report.

BACKGROUND: Tension pneumoperitonium is a rare complication during bronchoscopy that can cause acute respiratory and hemodynamic failure, with fatal consequences. Isolated pneumoperitonium during bronchoscopy usually results from ruptures of the abdominal viscera that need surgical repair. Non-surgical pneumoperitoneum (NSP) refers to some pneumoperitoneum that could be relieved without surgery and only by conservative therapy. However, the clinical experience of managing tension pneumoperitonium during bronchoscopy is limited and controversial. CASE SUMMARY: A 51-year-old female was admitted to our hospital for cough with bloody sputum of seven days. On the 8th day of her admission, a bronchoscopy was arranged for bronchial-alveolar lavage to detect possible pathogens in the lower respiratory tract, as oxygen was delivered via a 12 F nasopharyngeal cannula, approximately 5-6 cm from the tip of the catheter, with a flow rate of 5-10 L/min. After four minutes of bronchoscopy, the patient suddenly vomited 20 mL of water, followed by severe abdominal pain, while physical examination revealed obvious abdominal distension, as well as hardness and tenderness of the whole abdomen, which was considered pneumoperitonium, and the bronchoscopy was terminated immediately. A computer tomography scan indicated isolated tension pneumoperitonium, and abdominal decompression was performed with a drainage tube, after which her symptoms were relieved. A multidisciplinary expert consultation discussed her situation and a laparotomy was suggested, but finally refused by her family. She had no signs of peritonitis and was finally discharged 5 d after bronchoscopy with a good recovery. CONCLUSION: The possibility of tension pneumoperitonium during bronchoscopy should be guarded against, and given its serious clinical consequences, cardiopulmonary instability should be treated immediately. Varied strategies could be adopted according to whether it is complicated with pneumothorax or pneumomediastinum, and the presence of peritonitis. When considering NSP, conservative therapy maybe a reasonable option with good recovery. An algorithm for the management of pneumoperitonium during bronchoscopy is proposed, based on the features of the case series reviewed and our case reported.

Optically transparent and microwave diffusion coding metasurface by utilizing ultrathin silver films.

The past few years have witnessed the great success of artificial metamaterials with effective medium parameters to control electromagnetic waves. Herein, we present a scheme to achieve broadband microwave low specular reflection with uniform backward scattering by using a coding metasurface, which is composed of a rational layout of subwavelength coding elements, via an optimization method. We propose coding elements with high transparency based on ultrathin doped silver, which are capable of generating large phase differences (∼180°) over a wide frequency range by designing geometric structures. The electromagnetic diffusion of the coding metasurface originates from the destructive interference of the reflected waves in various directions. Numerical simulations and experimental results demonstrate that low reflection is achieved from 12 to 18 GHz with a high angular insensitivity of up to ±40° for both transverse electric and transverse magnetic polarizations. Furthermore, the excellent visible transparency of the encoding metasurface is promising for various microwave and optical applications such as electronic surveillance, electromagnetic interference shielding, and radar cross-section reduction.

Systematic Comparison and Comprehensive Evaluation of 80 Amino Acid Descriptors in Peptide QSAR Modeling.

The peptide quantitative structure-activity relationship (QSAR), also known as the quantitative sequence-activity model (QSAM), has attracted much attention in the bio- and chemoinformatics communities and is a well developed computational peptidology strategy to statistically correlate the sequence/structure and activity/property relationships of functional peptides. Amino acid descriptors (AADs) are one of the most widely used methods to characterize peptide structures by decomposing the peptide into its residue building blocks and sequentially parametrizing each building block with a vector of amino acid principal properties. Considering that various AADs have been proposed over the past decades and new AADs are still emerging today, we herein query the following: is it necessary to develop so many AADs and do we need to continuously develop more new AADs? In this study, we exhaustively collect 80 published AADs and comprehensively evaluate their modeling performance (including fitting ability, internal stability, and predictive power) on 8 QSAR-oriented peptide sample sets (QPSs) by employing 2 sophisticated machine learning methods (MLMs), totally building and systematically comparing 1280 (80 AADs × 8 QPSs × 2 MLMs) peptide QSAR models. The following is revealed: (i) None of the AADs can work best on all or most peptide sets; an AAD usually performs well for some peptides but badly for others. (ii) Modeling performance is primarily determined by the peptide samples and then the MLMs used, while AADs have only a moderate influence on the performance. (iii) There is no essential difference between the modeling performances of different AAD types (physiochemical, topological, 3D-structural, etc.). (iv) Two random descriptors, which are separately generated randomly in standard normal distribution N(0, 1) and uniform distribution U(-1, +1), do not perform significantly worse than these carefully developed AADs. (v) A secondary descriptor, which carries major information involved in the 80 (primary) AADs, does not perform significantly better than these AADs. Overall, we conclude that since there are various AADs available to date and they already cover numerous amino acid properties, further development of new AADs is not an essential choice to improve peptide QSAR modeling; the traditional AAD methodology is believed to have almost reached the theoretical limit nowadays. In addition, the AADs are more likely to be a vector symbol but not informative data; they are utilized to mark and distinguish the 20 amino acids but do not really bring much original property information to these amino acids.

Correction to: The role of high load herpes simplex virus in patients with mechanical ventilation: a real hospital acquired viral lung infection needs antiviral therapy?

An amendment to this paper has been published and can be accessed via the original article.

Adjunctive corticosteroids may be associated with better outcome for non-HIV Pneumocystis pneumonia with respiratory failure: a systemic review and meta-analysis of observational studies.

BACKGROUND: Evidence supporting corticosteroids adjunctive treatment (CAT) for Pneumocystis jirovecii pneumonia (PCP) in non-HIV patients is highly controversial. We aimed to systematically review the literature and perform a meta-analysis of available data relating to the effect of CAT on mortality of PCP in non-HIV patients. METHODS: We searched Pubmed, Medline, Embase, and Cochrane database from 1989 through 2019. Data on clinical outcomes from non-HIV PCP were extracted with a standardized instrument. Heterogeneity was assessed with the I2 index. Pooled odds ratios and 95% confidence interval were calculated using a fixed effects model. We analyzed the impact of CAT on mortality of non-HIV PCP in the whole PCP population, those who had hypoxemia (PaO2 < 70 mmHg) and who had respiratory failure (PaO2 < 60 mmHg). RESULTS: In total, 259 articles were identified, and 2518 cases from 16 retrospective observational studies were included. In all non-HIV PCP cases included, there was an association between CAT and increased mortality (odds ratio, 1.37; 95% confidence interval 1.07-1.75; P = 0.01). CAT showed a probable benefit of decreasing mortality in hypoxemic non-HIV PCP patients (odds ratio, 0.69; 95% confidence interval 0.47-1.01; P = 0.05). Furthermore, in a subgroup analysis, CAT showed a significantly lower mortality in non-HIV PCP patients with respiratory failure compared to no CAT (odds ratio, 0.63; 95% confidence interval 0.41-0.95; P = 0.03). CONCLUSIONS: Our meta-analysis suggests that among non-HIV PCP patients with respiratory failure, CAT use may be associated with better clinical outcomes, and it may be associated with increased mortality in unselected non-HIV PCP population. Clinical trials are needed to compare CAT vs no-CAT in non-HIV PCP patients with respiratory failure. Furthermore, CAT use should be withheld in non-HIV PCP patients without hypoxemia.

Transparent Perfect Microwave Absorber Employing Asymmetric Resonance Cavity.

The demand for high-performance absorbers in the microwave frequencies, which can reduce undesirable radiation that interferes with electronic system operation, has attracted increasing interest in recent years. However, most devices implemented so far are opaque, limiting their use in optical applications that require high visible transparency. Here, a scheme is demonstrated for microwave absorbers featuring high transparency in the visible range, near-unity absorption (≈99.5% absorption at 13.75 GHz with 3.6 GHz effective bandwidth) in the Ku-band, and hence excellent electromagnetic interference shielding performance (≈26 dB). The device is based on an asymmetric Fabry-Pérot cavity, which incorporates a monolayer graphene and a transparent ultrathin (8 nm) doped silver layer as absorber and reflector, and fused silica as the middle dielectric layer. Guided by derived formulism, this asymmetric cavity is demonstrated with microwaves near-perfectly and exclusively absorbs in the ultrathin graphene film. The peak absorption frequency of the cavity can be readily tuned by simply changing the thickness of the dielectric spacer. The approach provides a viable solution for a new type of microwave absorber with high visible transmittance, paving the way towards applications in the area of optics.

High-transmittance double-layer frequency-selective surface based on interlaced multiring metallic mesh.

In this work, we proposed an optically transparent double-layer frequency-selective surface (FSS) based on interlaced multiring metallic mesh. By changing the large metal area of a conventional double-layer FSS into triangular-orthogonal distributed basic rings and nested rotated subrings, we achieved an FSS with high optical transmittance and low normalized high-order diffraction intensity while maintaining a flat passband and steep transition band. The results showed that our fabricated FSS had a normalized visible transmittance of 90.31%, stable filtering passband of ∼33.9 GHz, 3 dB bandwidth of 13.4 GHz, and uniform diffraction distribution, which are favorable characteristics for optically transparent FSS applications.

Highly Transparent and Broadband Electromagnetic Interference Shielding Based on Ultrathin Doped Ag and Conducting Oxides Hybrid Film Structures.

Reducing electromagnetic interference (EMI) across a broad radio frequency band is crucial to eliminate adverse effects of increasingly complex electromagnetic environment. Current shielding materials or methods suffer from trade-offs between optical transmittance and EMI shielding capability. Moreover, poor mechanical flexibility and fabrication complexity significantly limit their further applications in flexible electronics. In this work, an ultrathin (8 nm) and continuous doped silver (Ag) film was obtained by introducing a small amount of copper during the sputtering deposition of Ag and investigated as transparent EMI shielding components. The electromagnetic Ag shielding (EMAGS) film was realized in the form of conductive dielectric-metal-dielectric design to relieve the electro-optical trade-offs, which transmits 96.5% visible light relative to the substrate and shows an excellent average EMI shielding effectiveness (SE) of ∼26 dB, over a broad bandwidth of 32 GHz, covering the entire X, Ku, Ka, and K bands. EMI SE >30 dB was obtained by simply stacking two layers of EMAGS films together and can be further improved up to 50 dB by separating two layers with a quarter-wavelength space. The flexible EMAGS film shows a stable EMI shielding performance under repeated mechanical bending. In addition, large-area EMAGS films were demonstrated by a roll-to-roll sputtering system, proving the feasibility for mass production. The high-performance EMAGS film holds great potential for various applications in wearable electronics, healthcare devices, and electronic safety areas.