The center of Israel presents a relatively simple vertical topographical cross-section: The eastern Mediterranean coast to the west, Judea and Samaria mountains in the center and the deep and steep Jordan valley to the east. Further to the east of the Jordan valley there is a plateau of the Moab mountains.

This work presents climatological examination of the daytime boundary layer height (BLH a.g.l) variability during non-summer months according to high resolution (3 km) WRF simulations during at least 5 years (2009-2013). Verification against radiosonde measurements at Beit Dagan at the central coastal plain has shown good agreement between predicted and measured variables including the BLH (mean absolute error 200-500 m).

The shape of monthly BLH histograms varies as a function of season and topography. During December-February the monthly BLH median above the mountain peak and its easterly slope is lower than that over the coastal area (0.3-1.2, 0.9-1.5 km), while during the transitional months September, October, May, the situation is reversed (0.9-1.8, 0.6-1.2 km). In order to track the reason behind the reduction of the BLH over the mountain peak during winter, an examination of the BLH variability during the local afternoon, 10-13 UTC, (12-15 LT) during the various months was performed. As a result, 8 test cases with relatively low (<350 m) BLH were isolated mainly during December. Weak pressure gradients and weak (< 5 m/s) easterly flows were found to be responsible for the low BLH. The synoptic pressure during these events is characterized by a ridge from the south in the middle troposphere and central Red Sea Trough or high to the east or to the north of Israel next to the surface. Foehn winds, which locally reduce the humidity and enhance the temperature, flow over the eastern slope of the Jordan valley and the western slope of the mountain. In such cases, the mild synoptic pressure gradients are responsible for the maintenance of the local cooling over the mountain peak. Limited warm air advection to the mountain peak and close to zero sensible heat flux maintain relatively cold air over the mountain peak and its eastern slope. This examination gives insights into the mechanism of shallow winter day time boundary layer events over the mountain peak and serves as a starting point for further research.

Background: Rift Valley fever virus (RVFV) is a zoonotic virus that poses a significant threat to both livestock and human health and has caused outbreaks in endemic regions. In humans, most patients experience a febrile illness; however, in some patients, RVF disease may result in hemorrhagic fever, retinitis, or encephalitis. While several veterinary vaccines are being utilized in endemic countries, currently, there are no licensed RVF vaccines or therapeutics for human use. Neutralizing antibodies specifically targeting vulnerable pathogen epitopes are promising candidates for prophylactic and therapeutic interventions. In the case of RVFV, the surface glycoproteins Gc and Gn, which harbor neutralizing epitopes, represent the primary targets for vaccine and neutralizing antibody development. Methods: We report the implementation of advanced 10x Genomics technology, enabling high-throughput single-cell analysis for the identification of rare and potent antibodies against RVFV. Following the immunization of mice with live attenuated rMP-12-GFP virus and successive Gc/Gn boosts, memory B cell populations (both general and antigen-specific) were sorted from splenocytes by flow cytometry. Deep sequencing of the antibody repertoire at a single-cell resolution, together with bioinformatic analyses, was applied for BCR pair selection based on their abundance and specificity. Results: Twenty-three recombinant monoclonal antibodies (mAbs) were selected and expressed, and their antigen-binding capacities were characterized. About half of them demonstrated specific binding to their cognate antigen with relatively high binding affinities. Conclusions: These antibodies could be used for the future development of efficacious therapeutics, as well as for studying virus-neutralizing mechanisms. The current study, in which the single-cell sequencing approach was implemented for the development of antibodies targeting the RVFV surface proteins Gc and Gn, demonstrates the effective applicability of this technique for antibody discovery purposes.

In this study, we assess an alternative Fc-fusion protein purification method that does not rely on chromatographic media or ligands. Recombinant human acetylcholinesterase, fused to the Fc domain of human IgG1 (henceforth, AChE-Fc), was purified with precipitated aromatic complexes composed of the bathophenanthroline (henceforth, batho) chelator with either Zn2+ or Cu2+ ions (i.e., [(batho)3:Zn2+] or [(batho)2:Cu2+]) in the presence of polyethylene glycol 6000 (PEG-6000). In a three-step purification process conducted at pH 7, AChE-Fc was captured by the aromatic complexes (Step 1); unbound or weakly bound protein impurities were removed with 20 mM NaCl (Step 2); and AChE-Fc was then extracted at pH 7 (Step 3) using 100 mM Na citrate buffer in 250 mM NaCl. Purified AChE-Fc was not aggregated (as determined by dynamic light scattering (DLS) and Native PAGE). However, full enzymatic activity was only preserved with the [(batho)3:Zn2+] complex. Interaction between AChE-Fc and [(batho)3:Zn2+] led to ~83–88% overall protein yield. Thirty-fold process upscaling by volume required only proportional increase in the amounts of [(batho)3:Zn2+] and PEG-6000. Efficient (95–97%) chelator recycling was achieved by recrystallization. Chelator leaching into purified AchE-Fc was estimated to be ~0.3% relative to the total amount used. Taken together, this novel procedure has the potential to provide an economical and practical avenue for the industrial purification of Fc-fusion proteins.

A major challenge in accidental or unregulated releases is the ability to identify the pollutant source, especially if the location is in a large industrial area. Usually in such cases, only a few sensors provide non-zero signal. A crucial issue is therefore the ability to use a small number of sensors in order to identify the source location and rate of emission. The general problem of characterizing source parameters based on real-time sensors is known to be a difficult task. As with many inverse problems, one of the main obstacles for an accurate estimation is the non-uniqueness of the solution, induced by the lack of sufficient information. In this study, an efficient method is proposed that aims to provide a quantitative estimation of the source of hazardous gases or breathable aerosols. The proposed solution is composed of two parts. First, the physics of the atmospheric dispersion is utilized by a well-established Lagrangian stochastic model propagated backward in time. Then, a new algorithm is formulated for the prediction of the spacial expected uncertainty reduction gained by the optimal placement of an additional sensor. These two parts together are used to construct an adaptive decision support system for the dynamical deployment of detectors, allowing for an efficient characterization of the emitting source. This method has been tested for several scenarios and is shown to significantly reduce the uncertainty that stems from the insufficient information.

Combined therapies in cancer treatment aim to enhance antitumor activity. However, delivering multiple small molecules imposes challenges, as different drugs have distinct pharmacokinetic profiles and tumor penetration abilities, affecting their therapeutic efficacy. To circumvent this, poly(lactic-co-glycolic acid) (PLGA)–polyethylene glycol (PEG)–based nanoparticles were developed as a platform for the codelivery of synergistic drug ratios, improving therapeutic efficacy by increasing the percentage of injected dose reaching the tumor. Nonetheless, extravasation-dependent tumor accumulation is susceptible to variations in tumor vasculature; therefore, PLGA-PEG was modified with sulfates to actively target P-selectin–expressing cancers. Here, we show the potential of our platform in unique three-dimensional (3D) in vitro and in vivo models. The P-selectin–targeted nanoparticles showed enhanced accumulation in 3D spheroids and tissues of P-selectin–expressing BRAF-mutated melanomas and BRCA-mutated breast cancers, resulting in superior in vivo efficacy and safety. This nanoplatform could advance the codelivery of a plethora of anticancer drug combinations to various P-selectin–expressing tumors.

We developed a selective technique to rapidly measure free chlorine, which is the sum of elemental chlorine (Cl₂), hypochlorous acid (HOCl), and hypochlorite (OCl⁻) in water samples via an electrophilic aromatic substitution reaction hyphenated with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Sample preparation involved derivatization at 25 °C for 15 min with 3,4,5-trimethoxyphenylacetic acid (TMPAA) in an aqueous solution prior to analysis. Several parameters were evaluated to determine the optimized reaction and for the production of informative MS/MS spectrum of the derivatization product, 2-chloro-3,4,5-trimethoxyphenylacetic acid (Cl-TMPAA). The resulting Cl-TMPAA derivative displayed an informative ESI-MS/MS spectrum characterized by product ions at m/z 232.0142, 200.0245, and 185.0009 from the precursor ion at m/z 259.0379. The linear dynamic range of the method (0.1–10 µg/mL) was fitted to concentration levels relevant to forensic toxicology issues. Compared with other analytical techniques, this newly established LC-MS-based method demonstrated specificity, simplicity, and rapidity. This method enables the detection of free chlorine for forensic investigations in criminal cases.

Stable isotope labeling (SIL) is a powerful tool for probing cellular metabolism and has been increasingly employed for metabolite annotation in mass spectrometry-based metabolomics. Herein, we outline the principles and methods of designing and performing SIL-based experiments in metabolomics studies. Further, we summarize different SIL approaches and highlight recent examples of their use for metabolite annotation, including biological feature recognition, degenerate feature annotation, elemental composition determination and metabolite structure elucidation, across diverse biological systems. Throughout, the opportunities, open challenges, and potential pitfalls of each SIL workflow are discussed. Finally, we summarize and compare the recently developed software tools for the analysis of SIL-based metabolomics data.

Rationale

Tramadol (T) is a strong painkiller drug that belongs to the opioid analgesic group. Several accidental intoxication cases after oral administration of T have been reported in the past decade. Tramadol, its derivatives, and metabolites present information-limited mass spectra with one prominent peak representing the amine-containing residue; therefore, their structural determination based on both electron impact mass spectrometry (EI-MS) and ESI-MS/MS spectra could be misleading.

Methods

A novel analytical method for the structural elucidation of tramadol, its four homologs, and its two main phase I metabolites (N-desmethyltramadol and O-desmethyltramadol) was developed using chemical modification and liquid chromatography–high-resolution tandem mass spectrometry (LC-HR-MS/MS) with Orbitrap technology.

Results

After chemical derivatization, each of the investigated T series exhibited informative mass spectra that enabled better exposition of their structures. The developed method was successfully implemented to explicitly identify the structures of tramadol and its N-desmethyltramadol metabolite in urine samples at low ng/mL levels.

Conclusions

An efficient derivatization-aided strategy was developed for rapidly elucidating the structure of tramadol-like compounds. The method is intended to assist forensic chemists in better diagnosing T and its analogs and metabolites in clinical or forensic toxicology laboratories.

Anthrax is a fatal zoonotic disease caused by exposure to Bacillus anthracis spores. The CDC’s guidelines divide anthrax treatment into three categories according to disease progression: post-exposure prophylaxis (PEP), systemic, and systemic with a suspicion of CNS infection. While the prognosis for PEP or the early treatment of systemic anthrax is very good, ingress of the bacteria into the CNS poses a substantial clinical challenge. Here, we use rabbits to test the efficacy of a combined treatment of meropenem and doxycycline, which is the first choice in the CDC recommendations for treating systemic patients with an indication of CNS infection. In addition, we test the efficacy of the first-generation cephalosporin, cefazolin, in treating different stages of the disease. We found that the combination of doxycycline and meropenem is highly effective in treating rabbits in our inhalation model. Cefazolin was efficient only for PEP or systemic-stage treatment and not for CNS-infected animals. Our findings support the CDC recommendation of using a combination of doxycycline and meropenem for systemic patients with or without indications of CNS infection. We found that cefazolin is a decent choice for PEP or early-stage systemic disease but recommend considering using this antibiotic only if all other options are not available.

Persistent Dry Spells (PDS) during winter in the eastern Mediterranean are crucial to understanding the regional challenges of water resources and mitigating agricultural and economic impacts. Winter dry spells significantly affect ecosystem stability, public health, and socioeconomic conditions in a region susceptible to climate variability. Therefore, extending the forecast horizon of these extreme weather events to sub-seasonal time scales is a key challenge. With this aim, we examine the covariability of the sea surface temperature of the Indian Ocean and Persistent Dry Spells during winter over the eastern Mediterranean. The positive Indian Ocean Dipole (IOD) phase alters global circulation patterns, notably increasing the geopotential height at 500 hPa and the sea-level pressure over western Russia, eastern Europe, and the eastern Mediterranean during PDS events. Concurrently, the positive IOD phase enhances moisture fluxes and decreases sea level pressure and geopotential height at 500 hPa in the Western Mediterranean, suggesting increased cyclonic activity in that region. This type of activity probably influences the formation of PDS in the eastern Mediterranean through latent heating and the formation of ridges downstream of the cyclones. The baroclinic, subtropical, and polar regimes are large-scale synoptic regimes alternately prevailing during PDS events. Changes due to the DMI phase are not identical under these regimes and sometimes have opposite trends. The baroclinic regime is the most frequent regime during PDS events. Consequently, the average changes in pressure intensity during PDS events strongly resemble those during baroclinic days. Positive DMI case studies exemplify the effect of these large-scale regimes. We provide evidence for a link between the positive phase of IOD in December and the frequency of longer (> 15 days) PDS events. The normalized frequencies of persistent 15-20-day events under the positive dipole mode index (DMI) are 4-8% higher than the frequency of negative DMI. The frequencies of 6-7 day events are ~20% lower. Finally, we emphasize the sensitivity of persistent dry spells during winter to event definition, the chosen precipitation data source, and threshold definitions for climate indices. These considerations are essential for improving the accuracy of regional weather and climate predictions, further enhancing our understanding of the climatic impacts of IOD and other teleconnection patterns in the eastern Mediterranean and worldwide.