Quantitative Assessment of LNAPL Retention in Soil Porous Media

The presence of hydrocarbon contaminants in the vadose zone is a serious hazard for environment quality. Moreover, there is an urgent need for accurate and reliable knowledge of the hydraulics of hydrocarbon contaminants in porous media to enhance efficiency of NAPLs remediation methods. The objective of this study was to quantitatively assess the hydraulic properties of different porous media with petroleum, kerosene, diesel fuel, and gasoline. The related retention curves were then experimentally obtained. Parameters of the soils retention curves were obtained based on van Genuchten (1980), Brooks-Corey (1964), and Campbell (1974) retention models. The accuracy of models was then assessed by some statistics. The results indicated that, in most cases, air entry value was significantly increased in a petroleum retention curve despite the fact that it was decreased for other NAPLs. The pore size distribution parameters (i.e., n, m, λ, and 1/b) of diesel fuel, kerosene, and gasoline did not change considerably compared to water retention curve. The Leverett (1941) scaling function was adopted to scale soil-fluid retention curves data in two-phase systems. The results indicated that, except for a silty clay medium and petroleum, the Leverett (1941) J-function could scale the LNAPL retention curves based on the water retention curve data.     

Stem cell-based cell therapy for neuroprotection in stroke: A review

Neurological disorders, such as stroke, are triggered by a loss of neurons and glial cells. Ischemic stroke remains a substantial problem for industrialized countries. Over the previous few decades our understanding about the pathophysiology of stroke has enhanced, nevertheless, more awareness is required to advance the field of stroke recovery. Existing therapies are incapable to adequately relief the disease outcome and are not appropriate to all patients. Meanwhile, the majority of patients continue to show neurological deficits even subsequent effective thrombolysis, recuperative therapies are immediately required that stimulate brain remodeling and repair once stroke damage has happened. Cell therapy is emergent as a hopeful new modality for increasing neurological recovery in ischemic stroke. Numerous types of stem cells from various sources have been identified and their possibility and efficiency for the treatment of stroke have been investigated. Stem cell therapy in patients with stroke using adult stem cells have been first practiced in clinical trials since 15 years ago. Even though stem cells have revealed a hopeful role in ischemic stroke in investigational studies besides early clinical pilot studies, cellular therapy in human is still at a primary stage. In this review, we summarize the types of stem cells, various delivery routes, and clinical application of stem cell-based therapy for stroke treatment.     

Pathophysiological roles of chronic low‐grade inflammation mediators in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common hormonal imbalance disease in reproductive‐aged women. Its basic characteristics are ovulatory dysfunction and ovarian overproduction of androgens that lead to severe symptoms such as insulin resistance, hirsutism, infertility, and acne. Notwithstanding the disease burden, its underlying mechanisms remain unknown, and no causal therapeutic exists. In recent years, further studies showed that inflammation processes are involved in ovulation and play a key role in ovarian follicular dynamics. Visceral adipose tissue can cause inflammatory response and maintenance of the inflammation state in adipocytes by augmented production of inflammatory cytokines, monocyte chemoattractant proteins, and recruitment of the immune cell. Therefore, the PCOS can be related to a low‐grade inflammation state and inflammatory markers. Investigating the inflammatory processes and mediators that contribute to the commencement and development of PCOS can be a critical step for better understanding the pathophysiology of the disease and its treatment through inhibition or control of related pathways. In the present review, we discuss the pathophysiological roles of chronic low‐grade inflammation mediators including inflammasome‐related cytokines, interleukin‐1β (IL‐1β), and IL‐18 in PCOS development.     

Loss of Survivin in the Prostate Epithelium Impedes Carcinogenesis in a Mouse Model of Prostate Adenocarcinoma

The inhibitor of apoptosis protein survivin is expressed in most cancers. Using the conditional PTEN deletion mouse model, we previously reported that survivin levels increase with prostate tumor growth. Here we evaluated the functional role of survivin in prostate tumor growth. First, we demonstrated that mice lacking the survivin gene in prostate epithelium were fertile and had normal prostate growth and development. We then serially, from about 10–56 weeks of age, evaluated histopathologic changes in the prostate of mice with PTEN deletion combined with survivin mono- or bi-allelic gene deletion. While within this time period most of the animals with wild-type or monoallelic survivin deletion developed adenocarcinomas, the most severe lesions in the biallelic survivin deleted mice were high-grade prostatic intra-epithelial neoplasia with distinct histopathology. Many atypical cells contained large hypertrophic cytoplasm and desmoplastic reaction in the prostatic intra-epithelial neoplasia lesions of this group was minimal until the late ages. A reduced proliferation index as well as apoptotic and senescent cells were detected in the lesions of mice with compound PTEN/survivin deficiency throughout the time points examined. Survivin deletion was also associated with reduced tumor expression of another inhibitor of apoptosis member, the X-linked inhibitor of apoptosis. Our findings suggest that survivin participates in the progression of prostatic intraepithelial neoplasia to adenocarcinoma, and that survivin interference at the prostatic intraepithelial neoplasia stages may be a potential therapeutic strategy to halt or delay further progression.     

Spectrally-Tunable Directionality of Compact Optical Nanoantennas

We propose a novel design of plasmonic compact nanoantenna with an efficiently engineered spectral response for the directive emission or harvesting of light. The nanoantenna comprised of four gold nanodisks, arranged longitudinally, and appropriately spaced. Interestingly, by tuning of the inter-particle distances, it is found that the proposed nanoantenna shows either dual-band or broad-band unidirectional performances. These remarkable spectral effects are due to the tailored energies of the two hybridized out-of-phase LSPR modes and the intrinsic electromagnetic interactions. The theoretical predictions are obtained based on the modified coupled-dipole approximation method. In order to obtain more accurate theoretical results, the primary incident optical field seen by the smaller nanodisks are modified by taking into account the field-enhancement caused by the excited plasmons in the largest nanodisk when it is illuminated first. The theoretical results are confirmed by the electromagnetic simulations.     

Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) to Helicoverpa armigera (Lepidoptera: Noctuidae): Effect of prey and predator stages

Abstract Understanding predator–prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea (Stephens), preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa armigera Hübner. The first and second instar larvae of C. carnea exhibited type II functional responses against both prey stages. However, the third instar larvae of C. carnea showed a type II functional response to the first instar larvae of H. armigera, but a type III functional response to the eggs. For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate on the larvae was 1.015 ± 0.278/h, and the attack coefficient on the eggs was 0.036 ± 0.005. The handling times of the third instar larvae on larvae and eggs were 0.087 ± 0.009 and 0.071 ± 0.001 h, respectively. The highest predation rate was found for the third instar larvae of C. carnea on H. armigera eggs. Results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling H. armigera eggs and larvae. However, for a comprehensive estimation of the bio‐control abilities of C. carnea toward H. armigera, further field‐based studies are needed.     

Discovery of novel inhibitors of LEDGF/p75-IN protein–protein interactions

Human lens epithelium-derived growth factor (LEDGF)/p75 plays an important role in the HIV life cycle by stimulating integrase (IN)-led viral DNA integration into cellular chromosomes. Mechanistic studies show the majority of IN inhibitors chelate magnesium ions in the catalytic active site, a region topologically distant from the LEDGF/p75 binding site. Compounds disrupting the formation of LEDGF/p75 and IN complexes serve as a novel mechanistic approach different from current antiretroviral therapies. We previously built pharmacophore models mimicking LEDGF/p75 residues and identified four classes of LEDGF/p75-IN inhibitors. Substructure and similarity searches yielded additional LEDGF/p75-IN inhibitors containing an acylhydrazone moiety. The most potent of the acylhydrazones inhibited LEDGF/p75-IN interaction with an IC₅₀ value of 400 nM. We explored structure–activity relationships (SAR) and identified new acylhydrazones, hydrazines, and diazenes as lead molecules for further optimization. Two lead LEDGF/p75-IN inhibitors showed antiviral activity.     

Investigation of sex ratio and adult longevity of Habrobracon hebetor Say in relation to some conventional and biorational insecticides

Habrobracon hebetor Say (Hymenoptera: Braconidae) is one of the most important natural enemies that has been used for biological control of lepidopteran pests, so the sub-lethal effects of imidacloprid, abamactin and Bacillus thuringiensis Berliner (Bt) on progeny sex ratio (male/total) and adult longevity of H. hebetor were examined under laboratory conditions. It was found that the progeny sex ratio changed to male bias significantly by Bt treatment. Also, the adult longevity of the wasp was affected adversely by insecticides treatment and it was longest in Bt treatment. In conclusion, the current results indicated that the sub-lethal concentration of these insecticides affected the progeny sex ratio and adult longevity and the best strategies for reduction of hazard to the H. hebetor in combination with Bt is to avoid their application before Bt spraying.     

Active site binding modes of the beta-diketoacids: a multi-active site approach in HIV-1 integrase inhibitor design

Predicting a bioactive conformation of a ligand is of paramount importance in rational drug design. The task becomes very difficult when the receptor site possesses a region with unusual conformational flexibility. Significant conformational differences are present in the active site regions in the available crystal structures of the core domains of HIV-1 integrase (IN). Among all reported IN inhibitors, the β-diketoacid class of compounds has proved to be of most promise and indeed S-1360 was the first IN inhibitor to enter clinical studies. With an aim to predict the bioactive (active site bound) conformation of S-1360, we performed extensive docking studies using three different reported crystal structures where the active site or partial active site region was resolved. For comparison we extended our studies to include 5CITEP (the first compound cocrystallized with IN core domain) and a bis-diketoacid (BDKA). We found that the conformation of S-1360 when bound in one of the active sites matches that of the experimentally observed results of IN escape mutants resistant to S-1360. Therefore, we propose that this active site conformation is the biologically relevant conformation and can be used for the future structure-based drug design studies selectively targeting IN.