bluuebunny/crossref_metadata_2025 huggingface dataset:
Campylobacter spp. Prevalence in Santiago, Chile: A Study Based on Molecular Detection in Clinical Stool Samples from 2014 to 2019
Authors: Porte Lorena , Pérez Caricia , Barbé Mario , Varela Carmen , Vollrath Valeska , Legarraga Paulette , Weitzel Thomas
Published: March 2023

Campylobacter spp. is an emerging cause of infectious diarrhea worldwide. In South American countries such as Chile, its prevalence is underestimated due to inadequate detection methods. Gastrointestinal multiplex PCR panels (GMP) permit rapid and sensitive detection of bacterial pathogens and provide important epidemiological information. This study aimed to analyze Campylobacter epidemiology using the results of molecular methods and to compare molecular detection results to those of culture methods. We performed a retrospective, descriptive analysis of Campylobacter spp. detected in clinical stool samples between 2014–2019 by GMP and culture. Within 16,582 specimens examined by GMP, Campylobacter was the most prevalent enteropathogenic bacteria (8.5%), followed by Salmonella spp. (3.9%), Shigella spp./enteroinvasive Escherichia coli (EIEC) (1.9%), and Yersinia enterocolitica (0.8%). The highest Campylobacter prevalence occurred in 2014/2015. Campylobacteriosis affected more males (57.2%) and adults from 19–65 years (47.9%) and showed a bimodal seasonality with summer and winter peaks. In 11,251 routine stool cultures, Campylobacter spp. was detected in 4.6%, mostly C. jejuni (89.6%). Among 4533 samples tested by GMP and culture in parallel, GMP showed a superior sensitivity (99.1% versus 50%, respectively). The study suggests that Campylobacter spp. is the most frequent bacterial enteropathogen in Chile.
Household Surveillance for Norovirus Gastroenteritis in a Nicaraguan Birth Cohort: A Nested Case—Control Analysis of Norovirus Risk Factors
Authors: Vielot Nadja Alexandra , Zepeda Omar , Reyes Yaoska , González Fredman , Vinjé Jan , Becker-Dreps Sylvia , Bucardo Filemón
Published: March 2023

Norovirus causes a large proportion of pediatric acute gastroenteritis (AGE) worldwide, and no vaccines are currently available. To inform public health measures against norovirus gastroenteritis, we assessed risk factors in a case–control study nested in a birth cohort study in Nicaragua. Between June 2017 and January 2022, we followed children weekly for AGE episodes, and collected stool specimens from symptomatic children. Risk factors for AGE were collected during routine weekly visits. Norovirus was detected in stools using real-time reverse transcriptase polymerase chain reaction and positive specimens were genotyped using Sanger sequencing. We included 40 norovirus-positive AGE children matched 1:2 to controls and conducted bivariate and multivariable analyses of norovirus AGE risk factors. Among typeable norovirus infections, GII.4 were more severe than non-GII.4 (four/twenty-one vs. one/nine) and accounted for all emergency visits and hospitalizations. Adjusted conditional logistic regression found that female sex and higher length-for-age Z score were protective against norovirus AGE; a dirt floor in the home, sharing cups or bottles, and recent contact with someone with AGE symptoms were associated with norovirus AGE, though estimates were highly imprecise. Reducing contact with symptomatic persons and with saliva or other bodily fluids on cups or floors could reduce infant norovirus incidence.
Antiviral Mechanisms of N-Phenyl Benzamides on Coxsackie Virus A9
Authors: Laajala Mira , Kalander Kerttu , Consalvi Sara , Amamuddy Olivier Sheik , Bishop Özlem Tastan , Biava Mariangela , Poce Giovanna , Marjomäki Varpu
Published: March 2023

Enteroviruses are one of the most abundant groups of viruses infecting humans, and yet there are no approved antivirals against them. To find effective antiviral compounds against enterovirus B group viruses, an in-house chemical library was screened. The most effective compounds against Coxsackieviruses B3 (CVB3) and A9 (CVA9) were CL212 and CL213, two N-phenyl benzamides. Both compounds were more effective against CVA9 and CL213 gave a better EC50 value of 1 µM with high a specificity index of 140. Both drugs were most effective when incubated directly with viruses suggesting that they mainly bound to the virions. A real-time uncoating assay showed that the compounds stabilized the virions and radioactive sucrose gradient as well as TEM confirmed that the viruses stayed intact. A docking assay, taking into account larger areas around the 2-and 3-fold axes of CVA9 and CVB3, suggested that the hydrophobic pocket gives the strongest binding to CVA9 but revealed another binding site around the 3-fold axis which could contribute to the binding of the compounds. Together, our data support a direct antiviral mechanism against the virus capsid and suggest that the compounds bind to the hydrophobic pocket and 3-fold axis area resulting in the stabilization of the virion.
Association between Dupilumab and Conjunctivitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Authors: Lin Tzu-Yi , Wang Ching-Ya , Wang Fang-Ying , Kang Eugene Yu-Chuan , Hwang Yih-Shiou
Published: March 2023

Conjunctivitis is commonly reported in dupilumab users with atopic dermatitis (AD), and few studies have compared the risk of conjunctivitis among patients with different indications. This study aimed to investigate the association between dupilumab and conjunctivitis in various diseases. The protocol of this study was registered on PROSPERO (ID CRD42023396204). The electronic search of PubMed, Embase, Cochrane Library, and ClinicalTrials.gov was conducted for the period from their inception to January 2023. Only placebo-controlled, randomized controlled trials (RCTs) were included. The main outcome was the incidence of conjunctivitis during the study period. The subgroup analysis was performed for patients with AD and non-AD indications, which include asthma, chronic rhinosinusitis with nasal polyps, and eosinophilic esophagitis. In total, 23 RCTs involving 9153 patients were included for meta-analysis. Dupilumab users exhibited significantly higher risk of conjunctivitis (risk ratio [RR], 1.89; 95% confidence interval [CI], 1.34–2.67) than placebo users. Notably, significantly increased incidence of conjunctivitis was observed in the dupilumab group relative to the placebo group among patients with AD (RR, 2.43; 95% CI, 1.84–3.12) but not among patients with non-AD indications (RR, 0.71; 95% CI, 0.43–1.13). In conclusion, only dupilumab users with AD but not those with non-AD indications reported an elevated incidence of conjunctivitis.
Design, Synthesis and In Vitro Biological Activity of Novel C-7 Methylene Congeners of Furanoallocolchicinoids
Authors: Gracheva Iuliia A. , Svirshchevskaya Elena V. , Shchegravina Ekaterina S. , Malysheva Yulia B. , Sitdikova Alsu R. , Fedorov Alexey Yu.
Published: March 2023

A series of novel heterocyclic colchicine derivatives bearing a C-7 methylene fragment were synthesized via Wittig, Horner–Wadsworth–Emmons and Nenajdenko–Shastin olefination approaches. The in vitro biological activities of the most promising compounds were investigated using MTT assays and cell cycle analyses. Compounds with an electron withdrawing group on the methylene fragment exhibited substantial antiproliferative activity towards COLO-357, BxPC-3, HaCaT, PANC-1 and A549 cell lines. The spatial orientation of the substituent at the double bond significantly influenced its biological activity.
Encapsulated Phytomedicines against Cancer: Overcoming the “Valley of Death”
Authors: Brotons-Canto Ana , Urueña Claudia P. , Imbuluzqueta Izaskun , Luque-Michel Edurne , Martinez-López Ana Luisa , Ballesteros-Ramírez Ricardo , Rojas Laura , Fiorentino Susana
Published: March 2023

P2Et is the standardized extract of Caesalpinia spinosa (C. spinosa), which has shown the ability to reduce primary tumors and metastasis in animal models of cancer, by mechanisms involving the increase in intracellular Ca++, reticulum stress, induction of autophagy, and subsequent activation of the immune system. Although P2Et has been shown to be safe in healthy individuals, the biological activity and bioavailability can be increased by improving the dosage form. This study investigates the potential of a casein nanoparticle for oral administration of P2Et and its impact on treatment efficacy in a mouse model of breast cancer with orthotopically transplanted 4T1 cells. Animals were treated with either free or encapsulated oral P2Et orally or i.p. Tumor growth and macrometastases were evaluated. All P2Et treatments significantly delayed tumor growth. The frequency of macrometastasis was reduced by 1.1 times with P2Et i.p., while oral P2Et reduced it by 3.2 times and nanoencapsulation reduced it by 3.57 times. This suggests that nanoencapsulation led to higher doses of effective P2Et being delivered, slightly improving bioavailability and biological activity. Therefore, the results of this study provide evidence to consider P2Et as a potential adjuvant in the treatment of cancer, while the nanoencapsulation of P2Et provides a novel perspective on the delivery of these functional ingredients.
Influence of PEGDA Molecular Weight and Concentration on the In Vitro Release of the Model Protein BSA–FITC from Photo Crosslinked Systems
Authors: Rekowska Natalia , Wulf Katharina , Koper Daniela , Senz Volkmar , Seitz Hermann , Grabow Niels , Teske Michael
Published: March 2023

Novel 3D printing techniques enable the development of medical devices with drug delivery systems that are tailored to the patient in terms of scaffold shape and the desired pharmaceutically active substance release. Gentle curing methods such as photopolymerization are also relevant for the incorporation of potent and sensitive drugs including proteins. However, retaining the pharmaceutical functions of proteins remains challenging due to the possible crosslinking between the functional groups of proteins, and the used photopolymers such as acrylates. In this work, the in vitro release of the model protein drug, albumin–fluorescein isothiocyanate conjugate (BSA–FITC) from differently composed, photopolymerized poly(ethylene) glycol diacrylate (PEGDA), an often employed, nontoxic, easily curable resin, was investigated. Different PEGDA concentrations in water (20, 30, and 40 wt %) and their different molecular masses (4000, 10,000, and 20,000 g/mol) were used to prepare a protein carrier with photopolymerization and molding. The viscosity measurements of photomonomer solutions revealed exponentially increasing values with increasing PEGDA concentration and molecular mass. Polymerized samples showed increasing medium uptake with an increasing molecular mass and decreasing uptake with increasing PEGDA content. Therefore, the modification of the inner network resulted in the most swollen samples (20 wt %) also releasing the highest amount of incorporated BSA–FITC for all PEGDA molecular masses.
Polarization-Insensitive, Orthogonal Linearly Polarized and Orthogonal Circularly Polarized Synthetic Aperture Metalenses
Authors: Hu Jijian , Dong Zhenghong , Yang Xuanwen , Xia Lurui , Chen Xueqi , Lu Yan
Published: March 2023

Metalenses have attracted much attention from researchers because they are thin, multifunctional and easy to integrate. However, due to the limitation of fabrication techniques and the influence of working wavelength, it is difficult to realize a large aperture. In this paper, we design and simulate polarization-insensitive, orthogonal linearly polarized and orthogonal circularly polarized synthetic aperture metalenses. We use a synthetic aperture to improve the cutoff frequency of the metalens and achieve an equivalent large-aperture metalens. We compare the modulation transfer function and focusing efficiency of synthetic aperture metalenses with different array structures. This work provides an effective solution to the needs of large-aperture metalenses, and metalenses with different polarizations can play an important role in polarization imaging.
High-Quality Computational Ghost Imaging with a Conditional GAN
Authors: Zhao Ming , Zhang Xuedian , Zhang Rongfu
Published: March 2023

In this study, we demonstrated a framework for improving the image quality of computational ghost imaging (CGI) that used a conditional generative adversarial network (cGAN). With a set of low-quality images from a CGI system and their corresponding ground-truth counterparts, a cGAN was trained that could generate high-quality images from new low-quality images. The results showed that compared with the traditional method based on compressed sensing, this method greatly improved the image quality when the sampling ratio was low.
Seed Priming with Fullerol Improves Seed Germination, Seedling Growth and Antioxidant Enzyme System of Two Winter Wheat Cultivars under Drought Stress
Authors: Kong Haiyan , Meng Xiangzhan , Akram Nudrat Aisha , Zhu Fengru , Hu Jiaxing , Zhang Zhen
Published: March 2023

The application of carbon-based nanomaterials (CBNMs) in plant science and agriculture is a very recent development. Many studies have been conducted to understand the interactions between CBNMs and plant responses, but how fullerol regulates wheat subjected to drought stress is still unclear. In this study, seeds of two wheat cultivars (CW131 and BM1) were pre-treated with different concentrations of fullerol to investigate seed germination and drought tolerance. Our results indicate that the application of fullerol at certain concentrations (25–200 mg L−1) significantly promoted seed germination in two wheat cultivars under drought stress; the most significant effective concentration was 50 mg L−1, which increased the final germination percentage by 13.7% and 9.7% compared to drought stress alone, respectively. Wheat plants exposed to drought stress induced a significant decrease in plant height and root growth, while reactive oxygen species (ROS) and malondialdehyde (MDA) contents increased significantly. Interestingly, wheat seedlings of both cultivars grown from 50 and 100 mg L−1 fullerol-treated seeds were promoted in seedling growth under water stress, which was associated with lower ROS and MDA contents, as well as higher antioxidant enzyme activities. In addition, modern cultivars (CW131) had better drought adaptation than old cultivars (BM1) did, while the effect of fullerol on wheat had no significant difference between the two cultivars. The study demonstrated the possibility of improving seed germination, seedling growth and antioxidant enzyme activities by using appropriate concentrations of fullerol under drought stress. The results are significant for understanding the application of fullerol in agriculture under stressful conditions.
Functional Dissection of the Physiological Traits Promoting Durum Wheat (Triticum durum Desf.) Tolerance to Drought Stress
Authors: Ltaief Salim , Krouma Abdelmajid
Published: March 2023

In Tunisia’s arid and semi-arid lands, drought stress remains the most critical factor limiting agricultural production due to low and irregular precipitation. The situation is even more difficult because of the scarcity of underground water for irrigation and the climate change that has intensified and expanded the aridity. One of the most efficient and sustainable approaches to mitigating drought stress is exploring genotypic variability to screen tolerant genotypes and identify useful tolerance traits. To this end, six Tunisian wheat genotypes (Triticum durum Desf.) were cultivated in the field, under a greenhouse and natural light, to be studied for their differential tolerance to drought stress. Many morpho-physiological and biochemical traits were analyzed, and interrelationships were established. Depending on the genotypes, drought stress significantly decreased plant growth, chlorophyll biosynthesis, and photosynthesis; stimulated osmolyte accumulation and disturbed water relations. The most tolerant genotypes (salim and karim) accumulated more potassium (K) and proline in their shoots, allowing them to maintain better tissue hydration and physiological functioning. The osmotic adjustment (OA), in which potassium and proline play a key role, determines wheat tolerance to drought stress. The calculated drought index (DI), drought susceptible index (DSI), drought tolerance index (DTI), K use efficiency (KUE), and water use efficiency (WUE) discriminated the studied genotypes and confirmed the relative tolerance of salim and karim.
Genome-Wide Identification and Analysis of the MADS-Box Transcription Factor Genes in Blueberry (Vaccinium spp.) and Their Expression Pattern during Fruit Ripening
Authors: Wang Xuxiang , Huang Qiaoyu , Shen Zhuli , Baron Ghislain Christel , Li Xiaoyi , Lu Xiaoying , Li Yongqiang , Chen Wenrong , Xu Lishan , Lv Jinchao , Li Wenjian , Zong Yu , Guo Weidong
Published: March 2023

MADS-box is a class of transcriptional regulators that are ubiquitous in plants and plays important roles in the process of plant growth and development. Identification and analysis of blueberry MADS-box genes can lay a foundation for their function investigations. In the present study, 249 putative MADS-box genes were identified in the blueberry genome. Those MADS-box genes were distributed on 47 out of 48 chromosomes. The phylogenetic and evolutionary analyses showed that blueberry MADS-box genes were divided into 131 type I members and 118 type II members. The type I genes contained an average of 1.89 exons and the type II genes contained an average of 7.83 exons. Motif analysis identified 15 conserved motifs, of which 4 were related to the MADS domain and 3 were related to the K-box domain. A variety of cis-acting elements were found in the promoter region of the blueberry MADS-box gene, indicating that the MADS-box gene responded to various hormones and environmental alterations. A total of 243 collinear gene pairs were identified, most of which had a Ka/Ks value of less than 1. Nine genes belonging to SEP, AP3/PI, and AGL6 subfamilies were screened based on transcriptomic data. The expression patterns of those nine genes were also verified using quantitative PCR, suggesting that VcMADS6, VcMADS35, VcMADS44, VcMADS58, VcMADS125, VcMADS188, and VcMADS212 had potential functions in blueberry fruit ripening. The results of this study provide references for an in-depth understanding of the biological function of the blueberry MADS-box genes and the mechanism of blueberry fruit ripening.
Green Synthesis of Iron Oxide (Hematite) Nanoparticles and Their Influence on Sorghum bicolor Growth under Drought Stress
Authors: Ndou Nzumbululo , Rakgotho Tessia , Nkuna Mulisa , Doumbia Ibrahima Zan , Mulaudzi Takalani , Ajayi Rachel Fanelwa
Published: March 2023

Drought is a major abiotic stress that confronts plant growth and productivity, thus compromising food security. Plants use physiological and biochemical mechanisms to cope with drought stress, but at the expense of growth. Green-synthesized nanoparticles (NPs) have gained great attention in agriculture due to their environmental friendliness and affordability while serving as potential biofertilizers. This study investigates the role of hematite (αFe2O3) NPs, synthesized from Aspalathus linearis (rooibos), to improve Sorghum bicolor growth under drought stress. About 18 nm, spherical, and highly agglomerated hematite (αFe2O3) NPs were obtained. Sorghum seeds were primed with 5, 10, and 15 mg/L αFe2O3 NPs, and, after seven days of germination, the seedlings were transferred into potting soil, cultivated for fourteen days, and were subsequently water deprived (WD) for a further seven days. A reduction in plant height (78%), fresh (FW; 35%) and dry (DW; 36%) weights, and chlorophyll (chl) content ((total chl (81%), chla (135%), and chlb (1827%)) was observed in WD plants, and this correlated with low nutrients (Mg, Si, P, and K) and alteration in the anatomic structure (epidermis and vascular bundle tissues). Oxidative damage was observed as deep blue (O2●−) and brown (H2O2) spots on the leaves of WD plants, in addition to a 25% and 40% increase in oxidative stress markers (H2O2 and MDA) and osmolytes (proline and total soluble sugars), respectively. Seed priming with 10 mg/L αFe2O3 NPs improved plant height (70%), FW (56%), DW (34%), total Chl (104%), chla (160%) and chlb (1936%), anatomic structure, and nutrient distribution. Priming with 10 mg/L αFe2O3 NPs also protected sorghum plants from drought-induced oxidative damage by reducing ROS formation and osmolytes accumulation and prevented biomolecule degradation. The study concludes that green synthesized hematite NPs positively influenced sorghum growth and prevented oxidative damage of biomolecules by improving nutrient uptake and osmoregulation under drought stress.
Assessment of Physicochemical Parameters in Two Winegrapes Varieties after Foliar Application of ZnSO4 and ZnO
Authors: Daccak Diana , Lidon Fernando C. , Coelho Ana Rita F. , Luís Inês Carmo , Marques Ana Coelho , Pessoa Cláudia Campos , Brito Maria da Graça , Kullberg José Carlos , Ramalho José C. , Silva Maria José , Rodrigues Ana Paula , Campos Paula Scotti , Pais Isabel P. , Semedo José N. , Silva Maria Manuela , Legoinha Paulo , Galhano Carlos , Simões Manuela , Pessoa Maria Fernanda , Reboredo Fernando H.
Published: March 2023

One-third of the world’s population is suffering from “hidden hunger” due to micronutrient deficiency. Zinc is acquired through diet, leading its deficiency to the development of disorders such as retarded growth, anorexia, infections, and hypogeusia. Accordingly, this study aimed to develop an agronomic workflow for Zn biofortification on two red winegrapes varieties (cv. Castelão and Syrah) and determine the physicochemical implications for winemaking. Both varieties produced in Setúbal (Portugal) were submitted to four foliar applications of ZnSO4 or ZnO (900 and 1350 g ha−1, respectively), during the production cycle. At harvest, Zn biofortification reached a 4.3- and 2.3-fold increase with ZnO 1350 g ha−1 in Castelão and Syrah, respectively (although, with ZnSO4 1350 g ha−1 both varieties revealed an increase in Zn concentration). On a physiological basis, lower values of NDVI were found in the biofortified grapes, although not reflected in photosynthetic parameters with cv. Syrah shows even a potential benefit with the use of Zn fertilizers. Regarding physical and chemical parameters (density, total soluble solids, dry weight, and color), relative to the control no significant changes in both varieties were observed, being suitable for winemaking. It was concluded that ZnSO4 and ZnO foliar fertilization efficiently increased Zn concentration on both varieties without a negative impact on quality, but cv. Castelão showed a better index of Zn biofortification and pointed to a potentially higher quality for winemaking.
The Paeonia qiui R2R3-MYB Transcription Factor PqMYBF1 Positively Regulates Flavonol Accumulation
Authors: Zhang Yue , Duan Jingjing , Wang Qiaoyun , Zhang Min , Zhi Hui , Bai Zhangzhen , Zhang Yanlong , Luo Jianrang
Published: March 2023

Tree peony is a “spring colored-leaf” plant which has red leaves in early spring, and the red color of the leaves usually fades in late spring. Flavonols are one subgroup of flavonoids, and they affect the plant organs’ color as co-pigments of anthocyanins. To investigate the color variation mechanism of leaves in tree peony, PqMYBF1, one flavonol biosynthesis-related MYB gene was isolated from Paeonia qiui and characterized. PqMYBF1 contained the SG7 and SG7-2 motifs which are unique in flavonol-specific MYB regulators. Subcellular localization and transactivation assay showed that PqMYBF1 localized to the nucleus and acted as a transcriptional activator. The ectopic expression of PqMYBF1 in transgenic tobacco caused an observable increase in flavonol level and the anthocyanin accumulation was decreased significantly, resulting in pale pink flowers. Dual-luciferase reporter assays showed that PqMYBF1 could activate the promoters of PqCHS, PqF3H, and PqFLS. These results suggested that PqMYBF1 could promote flavonol biosynthesis by activating PqCHS, PqF3H, and PqFLS expression, which leads metabolic flux from anthocyanin to flavonol pathway, resulting in more flavonol accumulation. These findings provide a new train of thought for the molecular mechanism of leaf color variation in tree peony in spring, which will be helpful for the molecular breeding of tree peony with colored foliage.
Mercury Accumulation in Food Crops and Phytoremediation Potential of Wild Plants Thriving in Artisanal and Small-Scale Gold Mining Areas in Uganda
Authors: Ssenku Jamilu E. , Naziriwo Betty , Kutesakwe Jennifer , Mustafa Abubakar Sadik , Kayeera Derrick , Tebandeke Emmanuel
Published: March 2023

Mercury (Hg) has been used for millennia in artisanal and small-scale gold mining (ASGM) to extract gold from ore as an amalgam that is heated to recover gold. Since there is hardly any sustainable technology that can be used to recover it, the vast percentage of released Hg finds its way into the environment. Currently, ASGM is the largest source of mercury pollution on Earth. Mercury (Hg) is listed among the top 10 most harmful metals by the World Health Organization (WHO), and it is known to cause several neurological disorders in humans. Thus, Hg levels in environmental systems surrounding pollution hotspots such as ASGM mines need to be monitored to ensure their proper management and protect vulnerable ecosystems and human health. This work was aimed to study the level of Hg pollution in soils and plants thriving around ASGM mines in Eastern Uganda and to evaluate the Hg phytoremediation potential of the plants. The total Hg contents were determined for soils, food crops and wild plants growing around ASGM mines. The results for the pH, organic carbon (OC) and electric conductivity (EC) of the soils in the study area were comparable to those of the control soils. The soils in the studied ASGM areas exhibited high Hg concentrations ranging between 723 and 2067 folds more than those of the control soils. All soils were moderately to heavily contaminated according to geoaccumulation (Igeo) index values that ranged between 1.16 and 3.31. The results of this study also showed that the food crops and wild plants accumulated Hg levels that were above the 20 ng/g (0.02 ppm) permissible limit. This study revealed relatively higher levels of Hg in the aerial parts of the plants compared with the underground organs, which can be attributed to Hg deposition, entry through stomata and foliar adsorption. Mercury levels in 47% of the food crop samples were above the FAO/WHO permissible mercury limit of 0.5 µg/g. Similarly, medicinal plants accumulated Hg to levels that were several folds higher than the 0.2 ppm permissible limit of mercury in herbal materials of Canada. Interestingly, this study showed that some wild plant species, especially sedges, exhibited relatively higher levels of mercury accumulation than others thriving in the same environment, an indication that such plants could be utilized in the phytoremediation of Hg-contaminated sites.
Interactions between Soybean Trypsin Inhibitor and Chitosan in an Aqueous Solution
Authors: Zhang Yihao , Liu Ruijia , Li He , Li You , Liu Xinqi
Published: March 2023

Supramolecular structures obtained from protein–polysaccharide association may be applied to encapsulate bioactive compounds or to improve the physical stability and texture properties of colloid–based products. In this study, the interaction of 0.1 wt% soybean trypsin inhibitor (STI) with different concentrations of chitosan (CS) in aqueous solutions was investigated under different pH by the analysis of state diagram, turbidity, zeta potential, spectroscopy, and microstructure; the protective effect of STI–CS complex coacervates on STI stability in simulated gastric juice was also discussed. The results suggested that interactions between STI and CS could form soluble/insoluble complexes mainly through hydrophobic interactions (pH 4.0) or electrostatic interactions (pH 6.0). The CD spectra showed that the secondary structure of STI did not change significantly when CS with the same charge was mixed with STI, and the secondary structure of STI was slightly changed when CS with the opposite charge was mixed with STI. Simulated gastric digestion experiments showed that the complex formed by non-covalent bonding had a protective effect on the active protein. This study provides information about the effect of different CS concentrations and pH values on the formation of complexes of CS and STI in an aqueous solution and provides theoretical references for the construction of supramolecular-structured carrier substances based on CS and STI.
Modulation of the Lower Critical Solution Temperature of Thermoresponsive Poly(N-vinylcaprolactam) Utilizing Hydrophilic and Hydrophobic Monomers
Authors: Halligan Elaine , Zhuo Shuo , Colbert Declan Mary , Alsaadi Mohamad , Tie Billy Shu Hieng , Bezerra Gilberto S. N. , Keane Gavin , Geever Luke M.
Published: March 2023

Four-dimensional printing is primarily based on the concept of 3D printing technology. However, it requires additional stimulus and stimulus-responsive materials. Poly-N-vinylcaprolactam is a temperature-sensitive polymer. Unique characteristics of poly-N-vinylcaprolactam -based hydrogels offer the possibility of employing them in 4D printing. The main aim of this study is to alter the phase transition temperature of poly-N-vinylcaprolactam hydrogels. This research focuses primarily on incorporating two additional monomers with poly-N-vinylcaprolactam: Vinylacetate and N-vinylpyrrolidone. This work contributes to this growing area of research by altering (increasing and decreasing) the lower critical solution temperature of N-vinylcaprolactam through photopolymerisation. Poly-N-vinylcaprolactam exhibits a lower critical solution temperature close to the physiological temperature range of 34–37 °C. The copolymers were analysed using various characterisation techniques, such as FTIR, DSC, and UV-spectrometry. The main findings show that the inclusion of N-vinylpyrrolidone into poly-N-vinylcaprolactam increased the lower critical solution temperature above the physiological temperature. By incorporating vinylacetate, the lower critical solution temperature dropped to 21 °C, allowing for potential self-assembly of 4D-printed objects at room temperature. In this case, altering the lower critical solution temperature of the material can potentially permit the transformation of the 4D-printed object at a particular temperature.
Nanoparticles as Drug Delivery Systems: A Review of the Implication of Nanoparticles’ Physicochemical Properties on Responses in Biological Systems
Authors: Yusuf Azeez , Almotairy Awatif Rashed Z. , Henidi Hanan , Alshehri Ohoud Y. , Aldughaim Mohammed S.
Published: March 2023

In the last four decades, nanotechnology has gained momentum with no sign of slowing down. The application of inventions or products from nanotechnology has revolutionised all aspects of everyday life ranging from medical applications to its impact on the food industry. Nanoparticles have made it possible to significantly extend the shelf lives of food product, improve intracellular delivery of hydrophobic drugs and improve the efficacy of specific therapeutics such as anticancer agents. As a consequence, nanotechnology has not only impacted the global standard of living but has also impacted the global economy. In this review, the characteristics of nanoparticles that confers them with suitable and potentially toxic biological effects, as well as their applications in different biological fields and nanoparticle-based drugs and delivery systems in biomedicine including nano-based drugs currently approved by the U.S. Food and Drug Administration (FDA) are discussed. The possible consequence of continuous exposure to nanoparticles due to the increased use of nanotechnology and possible solution is also highlighted.
Bibliometric Analysis of the Use of Biodiesel Production from Essential Oils as Biofuels
Authors: Biberci Mehmet Ali
Published: March 2023

Second-generation biodiesel, which is produced from essential oil plants, has important advantages, including a high yield of biofuels and the potential to reduce greenhouse gas emissions. The goal of this research was to examine the profile of original and review articles on biodiesel production from essential oils using bibliometric analysis. The search strategy identified 186 relevant and available peer-reviewed publications from 1981 to 2023, which were downloaded from the Web of Science (WoS) database. The retrieved documents were analyzed using VOSviewer. China was the predominant country publishing those documents, followed by the United States, India, Australia, and France. The keyword cluster analysis indicated the presence of 10 main research topics: diesel, fuel, and engine performance; extraction of lipids from microalgae; biofuel production from essential oils; green chemistry; the pyrolysis process; bioethanol production from renewable raw materials; obtaining biodiesel from essential oils; essential oil extraction; obtaining biofuels; and supercritical fluid extraction for fuels. The top three authors were Rahman, S. M. A., Cantrell, C. L., and Zheljazkov, V.D. The results showed that study topics such as different biodiesel raw material sources, biodiesel conversion technology, and the performance and emission characteristics of second-generation biodiesel are gaining popularity, with the goal to achieve a sustainable and clean environment.
Analytical Model of Hydraulic Fracturing for Low Permeability Hot Dry Rock Reservoirs and DEM Simulation Base on Fluid-Solid Coupling
Authors: Fan Heng , Liu Peihang , Zhao Yating , Yang Shangyu , Zhao Xinbo
Published: March 2023

The formation of a rich underground-seam network is the key problem in the development of low-permeability hot dry rock (HDR) resources. Considering the lack of macroscopic continuum theory to study hydraulic fracturing having preset fracture-interface element, the particle-flow method of micro-mechanical discrete-element theory is introduced to simulate the mechanical behavior of hydraulic fracturing for HDR low permeability reservoirs. The reservoir is simulated as a round particle; the fracturing fluid movement is described by the seepage field equation, and rock movement is described by the displacement field equation. Finally, the particle-flow numerical model of hydraulic fracturing for HDR low permeability reservoirs is established under the condition of fluid-solid coupling: the model contains two parts (rock and fracture). Based on the parallel-bond model, a definition of micro-fractures of hydraulic fracturing is given. The relation between the fracturing effect and influence parameters is discussed. The results show that the fracture-initiation pressure is proportional to the magnitude of minimum horizontal stress, particle normal-contact stiffness, and particle normal- and tangential-connection strengths; the pressure is also independent of maximal horizontal stress and tangential contact stiffness. At the same time, the formation temperature of dry hot rock will reduce the strength of the rock, so particle-flow numerical models of hydraulic fracturing in different temperatures are discussed. Results show that fracture length and width show a trend of increase before decrease with the increase of injection pressure, an inverse relationship with minimums horizontal principal stress, and a positive relationship with HDR reservoir permeability.
Mystery and Humility in the Depths of Understanding of Reality
Authors: Pohar Borut
Published: March 2023

The scientific process of understanding natural phenomena such as evolution is an important tool for human progress, so it is good to know where it begins and where it ends, or where it leads. In this article, we put forward the observation that mysticism begins when, in understanding phenomena, we move into the intellectual realm of the unobservable and invisible material and personal life processes, which are interconnected in two ways. On the one hand, the material life processes, which can be contemplated mystically by means of scientific explanations, analogical models, and imagination, are the reason for the purposefulness of identities that are the fruit of personal processes. These are experts, professional and amateur scientists, and lay scientists who are attracted to identity precisely because of the material life processes in which they have an interest, enthusiasm, or passion. On the other hand, it is precisely their mental engagement with these material life processes through the mystical contemplation of the beautiful solutions to nature’s problems that makes them true since truth is classically conceived precisely as the correspondence between intellect and a thing. Discerning the truth of hypotheses, theories, mid-range theories, and meta-theories, however, requires humility at all levels because of the collective way of seeking truth. In this process of truth discernment, it is necessary to accept humbly that I may be wrong and that my neighbor may be right, which ultimately leads us to the mysticism of the Triune God’s merciful love.
Machine Learning Models for Approximating Downward Short-Wave Radiation Flux over the Ocean from All-Sky Optical Imagery Based on DASIO Dataset
Authors: Krinitskiy Mikhail , Koshkina Vasilisa , Borisov Mikhail , Anikin Nikita , Gulev Sergey , Artemeva Maria
Published: March 2023

Downward short-wave (SW) solar radiation is the only essential energy source powering the atmospheric dynamics, ocean dynamics, biochemical processes, and so forth on our planet. Clouds are the main factor limiting the SW flux over the land and the Ocean. For the accurate meteorological measurements of the SW flux one needs expensive equipment-pyranometers. For some cases where one does not need golden-standard quality of measurements, we propose estimating incoming SW radiation flux using all-sky optical RGB imagery which is assumed to incapsulate the whole information about the downward SW flux. We used DASIO all-sky imagery dataset with corresponding SW downward radiation flux measurements registered by an accurate pyranometer. The dataset has been collected in various regions of the World Ocean during several marine campaigns from 2014 to 2021, and it will be updated. We demonstrate the capabilities of several machine learning models in this problem, namely multilinear regression, Random Forests, Gradient Boosting and convolutional neural networks (CNN). We also applied the inverse target frequency (ITF) re-weighting of the training subset in an attempt of improving the SW flux approximation quality. We found that the CNN is capable of approximating downward SW solar radiation with higher accuracy compared to existing empiric parameterizations and known algorithms based on machine learning methods for estimating downward SW flux using remote sensing (MODIS) imagery. The estimates of downward SW radiation flux using all-sky imagery may be of particular use in case of the need for the fast radiative budgets assessment of a site.
Tree Species Classification Based on ASDER and MALSTM-FCN
Authors: Luo Hongjian , Ming Dongping , Xu Lu , Ling Xiao
Published: March 2023

Tree species classification based on multi-source remote sensing data is essential for ecological evaluation, environmental monitoring, and forest management. The optimization of classification features and the performance of classification methods are crucial to tree species classification. This paper proposes Angle-weighted Standard Deviation Elliptic Cross-merge Rate (ASDER) as a separability metric for feature optimization. ASDER uses mutual information to represent the separability metric and avoids the difficulty of differentiation caused by multiple ellipse centers and coordinate origins forming straight lines by angle weighting. In classification method, Multi-head Self-attention Long Short-Term Memory—Full Convolution Network (MALSTM-FCN) is constructed in this paper. MALSTM-FCN enhances the global correlation in time series and improves classification accuracy through a multi-head self-attention mechanism. This paper takes Beijing Olympic Forest Park (after this, referred to as Aosen) as the research area, constructs a tree species classification dataset based on an actual ground survey, and obtains a classification accuracy of 95.20% using the above method. This paper demonstrates the effectiveness of ASDER and MALSTM-FCN by comparing temporal entropy and LSTM-FCN and shows that the method has some practicality for tree species classification.
A Novel End-to-End Unsupervised Change Detection Method with Self-Adaptive Superpixel Segmentation for SAR Images
Authors: Ji Linxia , Zhao Jinqi , Zhao Zheng
Published: March 2023

Change detection (CD) methods using synthetic aperture radar (SAR) data have received significant attention in the field of remote sensing Earth observation, which mainly involves knowledge-driven and data-driven approaches. Knowledge-driven CD methods are based on the physical theoretical models with strong interpretability, but they lack the robust features of being deeply mined. In contrast, data-driven CD methods can extract deep features, but require abundant training samples, which are difficult to obtain for SAR data. To address these limitations, an end-to-end unsupervised CD network based on self-adaptive superpixel segmentation is proposed. Firstly, reliable training samples were selected using an unsupervised pre-task. Then, the superpixel generation and Siamese CD network were integrated into the unified framework to train them end-to-end until the global optimal parameters were obtained. Moreover, the backpropagation of the joint loss function promoted the adaptive adjustment of the superpixel. Finally, the binary change map was obtained. Several public SAR CD datasets were used to verify the effectiveness of the proposed method. The transfer learning experiment was implemented to further explore the ability to detect the changes and generalization performance of our network. The experimental results demonstrate that our proposed method achieved the most competitive results, outperforming seven other advanced deep-learning-based CD methods. Specifically, our method achieved the highest accuracy in OA, F1-score, and Kappa, and also showed superiority in suppressing speckle noise, refining change boundaries, and improving detection accuracy in a small area change.
Unsupervised Video Summarization Based on Deep Reinforcement Learning with Interpolation
Authors: Yoon Ui Nyoung , Hong Myung Duk , Jo Geun-Sik
Published: March 2023

Individuals spend time on online video-sharing platforms searching for videos. Video summarization helps search through many videos efficiently and quickly. In this paper, we propose an unsupervised video summarization method based on deep reinforcement learning with an interpolation method. To train the video summarization network efficiently, we used the graph-level features and designed a reinforcement learning-based video summarization framework with a temporal consistency reward function and other reward functions. Our temporal consistency reward function helped to select keyframes uniformly. We present a lightweight video summarization network with transformer and CNN networks to capture the global and local contexts to efficiently predict the keyframe-level importance score of the video in a short length. The output importance score of the network was interpolated to fit the video length. Using the predicted importance score, we calculated the reward based on the reward functions, which helped select interesting keyframes efficiently and uniformly. We evaluated the proposed method on two datasets, SumMe and TVSum. The experimental results illustrate that the proposed method showed a state-of-the-art performance compared to the latest unsupervised video summarization methods, which we demonstrate and analyze experimentally.
Measurement of Steroids in the Placenta, Maternal Serum, and Fetal Serum in Humans, Rats, and Mice: A Technical Note
Authors: Price Hayley R. , Jalabert Cecilia , Seib Désirée R. , Ma Chunqi , Lai Dickson , Soma Kiran K. , Collier Abby C.
Published: March 2023

Steroid hormones are vital for a successful pregnancy. The placenta is attached to the uterine wall and is the major organ of communication between the mother and the fetus through the umbilical cord and the transfer of compounds (including the production and actions of steroids) across the villous placenta. Therefore, a correct understanding and measurement of steroid levels across the maternal–placental–fetal interface is essential. We have experience spanning more than two decades and have published more than 40 papers using a variety of methods to assess circulating and placental steroid levels. In this review, we discuss various methods for steroid detection and quantitation, as well as their advantages and disadvantages. This document provides technical guidance for best practices that, in our estimation, can assist researchers in more easily and correctly performing these studies. Critical methodological considerations, including tissue collection, tissue processing, and analytical factors (sensitivity, selectivity, matrix effects, and internal standards), are covered. We highlight important differences between human and rodent tissues as they relate to steroid levels in pregnancy and the interpretation of results, and provide guidance for best practices in future studies.
Mechanical Behavior of Hydrated-Lime–Liquid-Stabilizer-Treated Granular Lateritic Soils
Authors: Tang Kangwei , Zeng Feng , Shi Liang , Zhu Long , Chen Zining , Zhang Feng
Published: March 2023

Granular lateritic soil is commonly used for road construction in humid tropical and subtropical regions. However, the high plastic clay content and poor particle distribution of some laterite materials make them unsuitable for bases and subbases. Lime treatment is a widely used method for improving problematic lateritic soil, and liquid ionic stabilizers are considered an environmentally friendly solution for reinforcing such soils. However, using only lime or only stabilizers may not be optimal. This study investigated the effect of treating granular lateritic soil with hydrated lime and a new liquid stabilizer, Zhonglu-2A (ZL-2A). A series of indoor tests, including compaction, California bearing ratio, and unconfined compressive strength tests, were conducted to evaluate the effects of hydrated lime content and stabilizer content on the mechanical properties, mineralogical composition, and microstructure of the soil. The results show that an increase in hydrated lime dosage increases the optimal moisture content and decreases the maximum dry density. The CBR of lime-stabilizer-treated laterite was at least 2–3 times higher than that of the only-lime-treated soil. The highest CBR was observed in samples treated with 0.2‰ ZL-2A stabilizer. The sample with 6% lime and 0.2‰ ZL-2A stabilizer exhibited the highest unconfined compressive strength, and a nearly linear increase was observed between the unconfined compressive strength and CBR. Further investigation of the stabilization mechanism using X-ray diffraction mineralogy analysis and scanning electron microscopy revealed that the inorganic substances of the ZL-2A stabilizer and the hydrated lime provided the basic conditions for the reaction and generated cementitious hydrates on the clay particles. The mixture of granular lateritic soil and hydrated lime was wrapped by the ZL-2A stabilizer, forming a complex spatial structure and improving the strength of the soil. To improve the bearing capacity of subgrades in actual subgrade engineering, a combination of a liquid ionic stabilizer and lime should be used to treat laterite.