bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Cationic Surfactants Mineralization by Ozonation and Photo‐Fenton Process
Authors: Dantas Renato F. , Darcissac Marylin , Lesueur Céline , Contreras Sandra , Sans Carme , Fuerhacker Maria , Esplugas Santiago
Published: February 2009

Aqueous solutions of two important quaternary ammonium compounds—16‐BAC (benzyl‐dimethyl‐hexadecylammonium‐chloride) and 18‐BAC (benzyl‐dimethyl‐stearylammonium‐chloride)—were treated by the ozonation and photo‐Fenton processes at different ozone doses and hydrogen peroxide concentrations, respectively. During the photo‐Fenton experiments, two different types of lamps were used—a UV mercury vapor medium pressure lamp and a xenon lamp, which simulates solar radiation. The total organic carbon removal was monitored to follow the mineralization of the surfactants. According to the experimental results, after 90 minutes of treatment, the photo‐Fenton process achieved up to 80% of mineralization when the UV lamp was used. The efficiency of the photo‐Fenton with the xenon lamp was lower. The ozonation process reached, at most, 50% mineralization at the used conditions (ozone dose = 7.57 g/h).
Adhesion of Escherichia coli to Iron‐Coated Sand in the Presence of Humic Acid: A Column Experiment
Authors: Park Seong‐Jik , Kim Song‐Bae
Published: February 2009

Column experiments were performed to examine the influence of humic acid on the attachment of Escherichia coli to iron‐coated sand. Results show that, in the coated sand, the average mass recovery was 2.9% in deionized water and increased sharply to 94.6% at a humic acid concentration of 16 mg/L. In leaching solution containing both humic acid and phosphate, the mass recovery increased from 26.0 to 94.6%, by increasing the portion of humic acid from 0 to 100% (from 0 to 16 mg/L). In addition, the mass recovery (94.6%) at a humic acid concentration of 16 mg/L was much larger than that (26.0%) at the same concentration of phosphate. This study presents information regarding the role of humic acid in the adhesion of bacteria to iron‐coated sand and helps to enhance the knowledge of bacterial removal in positively charged porous media.
Maximizing Sorbent Life: Comparison of Columns in Parallel, Lead‐Lag Series, and with Bypass Blending
Authors: Denning Patrick C. , Dvorak Bruce I.
Published: February 2009

Various adsorption column configurations can be used to increase fractional utilization and decrease adsorbent usage rate. This study compared the adsorbent usage rate of different column configurations. Mathematical models simulated chromatographic breakthrough front shapes and determined adsorbent usage rates. A configuration selection diagram based on percent mass‐transfer zone (MTZ) and target C/ C o (effluent concentration/influent concentration) was created to compare the adsorbent usage rate of configurations for single component systems. The target C/ C o determined the column configuration with the lowest adsorbent usage rate when the MTZ was a large percentage of the column (>60%), while all column configurations generally performed similarly at short percent MTZs (<30%). Bypass blending was found to be most effective with a lead‐lag configuration and the maximum amount of bypass. A sensitivity analysis determined that competitive adsorption can significantly change the configuration selection diagram and generally makes lead‐lag more competitive compared with parallel column configurations.
Peristaltic Pump Autosamplers for Solids Measurement in Stormwater Runoff
Authors: Clark Shirley E. , Siu Christina Y.S. , Pitt Robert , Roenning Christopher D. , Treese Daniel P.
Published: February 2009

Regulatory agencies approve automatic samplers containing peristaltic pumps as a sample collection method for stormwater characterization and for treatment‐device evaluation. Autosampler performance, as discussed in the limited available literature, can vary across the entire particle size range typically found in stormwater from different source areas and outfalls—reasonably consistent performance for particle sizes <250 μm, but much less consistency for particles >250 μm. Therefore, a series of experiments was undertaken to quantify the upper range of consistent particle capture that may occur with sampling stormwater suspended sediment and particulate‐bound pollutants. These experiments, based on triplicate sampling at each experimental condition, found that peristaltic pump autosamplers commonly used in stormwater monitoring could not repeatedly and effectively capture particles >250 μm from a simulated stormwater whose particles have a specific gravity of 2.65. It was expected that the effective size for autosamplers would be correspondingly larger for particles having smaller specific gravities. The height of the sampler had no influence on particle recovery up to a height of 2.5 m, with slightly decreasing recoveries of large particles occurring at greater heights, as a result of reduced sampler intake velocity. Therefore, to characterize the solids across the entire size range and specific gravities that may occur in stormwater runoff, autosamplers should be deployed in conjunction with bedload and floatables sampling.
Effective Removal of Cryptosporidium by a Novel Bioflocculant
Authors: Ghosh Moushumi , Pathak Santosh , Ganguli Abhijit
Published: February 2009

Extracellular biopolymer produced from Klebsiella terrigena was found to have excellent flocculating ability over a wide range of colloid particles (0.5 to 25μ). The biopolymer was thermostable, with an optimum temperature for flocculation of 30°C. Analysis with Fourier transform infrared spectrophotometry (FT‐IR) shows that the biopolymer mainly possesses hydroxyl, carboxyl, and methoxyl groups, with neutral sugar and uronic acid as its major and minor components, and the structure of a polysaccharide. The average molecular weight of the biopolymer was greater than 2 × 10 3 kilodalton (KDa), as determined by gel permeation chromatography. Scanning electron microscopy indicated a porous morphology of the biopolymer. At a dosage of 2 mg/L, the purified biopolymer could remove 62.3% of Cryptosporidium oocysts (1 × 10 6) spiked in tap water samples. Calcium (5mM) was required for effective removal. The removal efficiency of Cryptosporidium oocysts by the biopolymer remained unaltered over a pH range of 6 to 8. The results of this study indicates a possible utility of the Klebsiella terrigena biopolymer as an alternative to typically used chemical flocculants for removal of Cryptosporidium oocysts from water.
Adsorbable Organic Halogens Generation and Reduction During Degradation of Phenol by UV Radiation/Sodium Hypochlorite
Authors: Zeng Qing‐fu , Fu Jie , Shi Yin‐tao , Xia Dong‐sheng , Zhu Hai‐liang
Published: February 2009

The degradation of phenol by UV radiation/sodium hypochlorite (UV/NaClO) was investigated. The degradation processes were analyzed by a UV‐visible spectrometer, total organic carbon analyzer, and gas chromatography‐mass spectroscopy. The experimental results indicate that phenol can be photodegraded by UV/NaClO effectively. However, adsorbable organic halogens (AOX) were produced during the degradation process. Analysis of the mechanism of degradation indicates that the decrease in pH value would increase the formation of AOX. Also, dissolved oxygen greatly increased the rate of phenol degradation and reduced the formation of AOX. Therefore, appropriate conditions could increase degradation and inhibit chlorination. Adjusting the pH value and increasing the amount of oxygen were effective methods.
Mechanisms of Manganese Removal from Wastewaters in Constructed Wetlands Comprising Water Hyacinth (Eichhornia crassipes (Mart.) Solms) Grown under Different Nutrient Conditions
Authors: Kularatne Ranil K. A. , Kasturiarachchi Jagath C. , Manatunge Jagath M. A. , Wijeyekoon Suren L. J.
Published: February 2009

This article discusses key mechanisms involved in removing 1 mg/L Mn from synthetic wastewaters in constructed wetlands comprising water hyacinth (Eichhornia crassipes (Mart.) Solms) grown under different nutrient levels of 1‐fold (28 mg/L and 7.7 mg/L of total nitrogen and total phosphorus, respectively), 2‐fold, 1/4‐fold, and 1/8‐fold. A mass balance was carried out to evaluate the key removal mechanisms. Phytoremediation mainly due to phytoextraction substantially contributed to manganese removal. However, chemical precipitation was absent, suggesting that manganese has a higher solubility in the given average pH (6.2 to 7.1) conditions in constructed wetlands. Bacterial mediated immobilization mechanisms also did not contribute to manganese removal. Sediments constituted a minor sink to manganese, implying that manganese has a poor adsorption potential. Constructed wetlands comprising water hyacinth are effective at removing manganese from wastewaters despite the fact that the plants are grown under higher or lower nutrient conditions.
Development of a Novel Circular Secondary Clarifier for Improving Solids Liquid Separation in Wastewater Treatment
Authors: Pophali G. R. , Kaul S. N. , Nandy T. , Devotta Sukumar
Published: February 2009

A novel circular secondary clarifier was developed to obviate the shortcomings of conventional clarifiers. The novel clarifier provides natural flocculation, which occurs as a result of hydraulic energy dissipation and the formation of sludge cloud referred to as plume. The efficiency of the clarifier depends on the stability of the plume, which in turn depends on the velocity gradient. For natural flocculation to occur, a velocity gradient of 10 to 15 s −1 was found to be favorable. This velocity also keeps the plume‐rise well below the free‐surface. The mean particle size of mixed liquor suspended solids increases from 41 to 83 μm in the plume, which indicates agglomeration of particles and confirms that natural flocculation is occurring within the plume. The hydraulic improvement achieved by improving inlet design dissipates hydraulic energy, uniformly distributes flow, minimizes sludge blanket disturbances, and promote flocculation. The improved clarifier operates at 1‐h hydraulic retention time.
John Dewey’s Influence on the Origins of the Social Studies: An Analysis of the Historiography and New Interpretation
Authors: Fallace Thomas
Published: February 2009

This article offers a critical review of the historical literature on the National Education Association’s (NEA) 1916 Committee on Social Studies (CSS) report, the document generally believed to have launched the social studies movement in American secondary schools. The review begins with a critical analysis of the four most pervasive interpretations of the report. Drawing upon these interpretations, the author suggests that there are three central issues at the heart of these disputes. The first is over the ideological origins of the report; the second, its institutional origins; and the third, its epistemological position. It is argued that the influence of John Dewey is the key to overcoming these disagreements by suggesting that the members of the Committee agreed upon a core of shared beliefs that reflected his philosophical ideas.
Regulation of Epithelial Na+ Channel (ENaC) in the Salivary Cell Line SMG-C6
Authors: Vasquez Margarita M. , Mustafa Shamimunisa B. , Choudary Ahsan , Seidner Steve R. , Castro Robert
Published: February 2009

Glucocorticoids and mineralocorticoids modulate Na+ transport via epithelial Na+ channels (ENaC). The rat submandibular epithelial cell line, SMG-C6, expresses α-ENaC mRNA and protein and exhibits amiloride-sensitive Na+ transport when grown in low-serum (2.5%) defined medium, therefore, we examined the effects of altering the composition of the SMG-C6 cell growth medium on ENaC expression and function. No differences in basal or amiloride-sensitive short-circuit current (Isc) were measured across SMG-C6 monolayers grown in the absence of thyroid hormone, insulin, transferrin, or EGF. In the absence of hydrocortisone, basal and amiloride-sensitive Isc significantly decreased. Similarly, monolayers grown in 10% serum-supplemented medium had lower basal Isc and no response to amiloride. Adding hydrocortisone (1.1 μM) to either the low or 10% serum medium increased basal and amiloride-sensitive Isc, which was blocked by RU486, the glucocorticoid and progesterone receptor antagonist. Aldosterone also induced an increase in α-ENaC expression and Na+ transport, which was also blocked by RU486 but not by the mineralocorticoid receptor antagonist spironolactone. Thus, in the SMG-C6 cell line, hydrocortisone and aldosterone increased ENaC expression and basal epithelial Na+ transport. The absence of endogenous ENaC expression in culture conditions devoid of steroids makes the properties of this cell line an excellent model for investigating pathways regulating ENaC expression and Na+ transport.
Hyperthermia-Induced Cardioprotection Is Potentiated by Ischemic Postconditioning in Rats
Authors: Murozono Yukichi , Takahashi Naohiko , Shinohara Tetsuji , Ooie Tatsuhiko , Teshima Yasushi , Hara Masahide , Saikawa Tetsunori , Yoshimatsu Hironobu
Published: February 2009

We tested the hypothesis that the protective effects of hyperthermia (HT) could be augmented by ischemic postconditioning (PostC) via enhancement of reperfusion-induced Akt phosphorylation. The role of the mitoKATP channel as an effecter to protect hearts against ischemia/reperfusion injury was also investigated. In isolated perfused heart experiments using a Langendorff apparatus, 30 min of no-flow global ischemia was followed by 120 min of reperfusion. Ischemic PostC, 5 cycles of 10-sec reperfusion/10-sec ischemia, was achieved at the initial moment of reperfusion. Hyperthermia (HT, 43°C for 20 min) was applied 24 hr before ischemia onset. Ischemic PostC alone did not show significant protection, but HT did. The HT-induced protection in terms of infarct size, recovery of left ventricular performance, amount of released creatine kinase and apoptosis were enhanced by ischemic PostC. These protective effects were consistent with the levels of Akt phosphorylation 7 min after reperfusion and were completely blocked by the pretreatment with the phosphatidylinositol 3-kinase inhibitor wortmannin. HT-induced protection was also completely abolished by concomitant perfusion with 5-hydroxydecanoate (5HD, 100 μM), an inhibitor of the mitochondrial ATP-sensitive potassium (mitoKATP) channel. However, the potentiated protection by ischemic PostC remained, even in the presence of 5HD. In conclusion, ischemic PostC could potentiate the protective effects of HT possibly via enhancement of reperfusion-induced Akt phosphorylation. Although the opening of the mitoKATP channel is predominantly involved as an effecter in HT-induced protection, potentiated protection by ischemic PostC may involve mechanisms other than the mitoKATP channel.
Endogenous Hydrogen Sulfide Regulates Pulmonary Artery Collagen Remodeling in Rats with High Pulmonary Blood Flow
Authors: Li Xiaohui , Jin Hongfang , Bin Geng , Wang Li , Tang Chaoshu , Du Junbao
Published: February 2009

The mechanisms responsible for the structural remodeling of pulmonary vasculature induced by increased pulmonary blood flow are not fully understood. This study explores the effect of endogenous hydrogen sulfide (H2S), a novel gasotransmitter, on collagen remodeling of the pulmonary artery in rats with high pulmonary blood flow. Thirty-two Sprague-Dawley rats were randomly divided into sham, shunt, sham+PPG (D,L-propargylglycine, an inhibitor of cystathionine-γ-lyase), and shunt+PPG groups. After 4 weeks of shunting, the relative medial thickness (RMT) of pulmonary arteries and H2S concentration in lung tissues were investigated. Collagen I and collagen III were evaluated by hydroxyproline assay, sirius-red staining, and immunohistochemistry. Pulmonary artery matrix metalloproteinase-13 (MMP-13), tissue inhibitor of metalloproteinase-1 (TIMP-1), and connective tissue growth factor (CTGF) were evaluated by immunohistochemistry. After 4 weeks of aortocaval shunting, resulting in an elevation of lung tissue H2S to 116.4%, rats exhibited collagen remodeling and increased CTGF expression in the pulmonary arteries. Compared with those of the shunt group, lung tissue H2S production was lowered by 23.4%, RMT of the pulmonary artery further increased by 39.5%, pulmonary artery collagen accumulation became obvious, and pulmonary artery CTGF expression elevated ( P < 0.01) in the shunted rats treated with PPG. However, pulmonary artery MMP-13 and TIMP-1 expressions decreased significantly in rats of shunt+PPG group ( P < 0.01). This study suggests that endogenous H2S exerts an important regulatory effect on pulmonary collagen remodeling induced by high pulmonary blood flow.
Taurocholate Feeding to Bile Duct Ligated Rats Prevents Caffeic Acid-Induced Bile Duct Damage by Changes in Cholangiocyte VEGF Expression
Authors: Mancinelli Romina , Onori Paolo , Gaudio Eugenio , Franchitto Antonio , Carpino Guido , Ueno Yoshiyuki , Alvaro Domenico , Annarale Luigi P , DeMorrow Sharon , Francis Heather
Published: February 2009

Cholangiocytes are the target cells in cholestatic models of ductal hyperplasia including bile duct ligation (BDL). We have shown that: (i) cholangiocytes express VEGFR-2 and VEGFR-3; (ii) VEGF-A and VEGF-C stimulate cholangiocyte proliferation via an autocrine mechanism; and (iii) chronic administration of VEGF-A prevents cholangiocyte damage induced by hepatic artery ligation. Caffeic acid phenethyl ester (CAPE) induces growth inhibition in different cells. Taurocholic acid (TC) protects cholangiocytes against injury induced by parasympathetic or sympathetic denervation. The aims of this study were to determine if: (i) CAPE induces bile duct damage; and (ii) TC prevents CAPE-induced bile duct damage by increasing cholangiocyte VEGF expression. Methods: Normal and BDL rats (immediately after surgery) were fed 1% TC or control diet in the absence/presence of daily IP injections of CAPE (10 mg/Kg BW). One week later, we evaluated: (i) cholangiocyte apoptosis, proliferation and ductal mass in liver sections; (ii) functional activity by measuring secretin-stimulated bile and bicarbonate secretion; and (iii) VEGF-A/C and VEGFR-2/R-3 expression in liver sections. In vitro, BDL cholangiocytes were exposed to CAPE (40 μM) in the absence/presence of TC (40 μM) with and without pretreatment with VEGF receptor inhibitors before evaluating cholangiocyte apoptosis and proliferation. Results: Chronic CAPE administration to BDL rats increased cholangiocyte apoptosis and decreased ductal mass. This effect was associated with reduced expression of VEGF-A, VEGF-C, VEGFR-2 and VEGFR-3. In vivo, TC feeding partly prevented CAPE-induced changes in cholangiocyte apoptosis and growth and loss of ductal secretion. The protective effect of TC was associated with enhanced VEGF-A, VEGF-C, VEGFR-2 and VEGFR-3. In vitro, TC partially prevented CAPE-induced increases in apoptosis and decreases in cholangiocyte proliferation. These changes were reversed by pretreatment with VEGF-receptor inhibitors. Conclusion: Manipulation of cholangiocyte VEGF expression by bile acids may be important in preventing the impairment of cholangiocyte proliferation by exogenous agents.
The Source and Secretion of Immunoactive Relaxin in Rat Milk
Authors: Steinetz Bernard G. , Horton Lori , Lasano Sally
Published: February 2009

The milk of many mammalian species contains hormones and growth factors in addition to nutrients and immuocompetent substances. These factors can be absorbed into the circulation of suckling neonates to exert important effects on metabolism and promote tissue and organ growth. Frequently, there is uncertainty as to whether such substances are gene products of the mammary glands themselves or are produced elsewhere and concentrated from the systemic circulation. The 6 kD polypeptide, relaxin, appears in milk of several mammalian species, including that of the rat, but proof of its source of secretion (corpus luteum vs. mammary gland) is so far lacking. The specific monoclonal anti-rat relaxin antibody MCA1 has previously been utilized successfully to investigate many of relaxin’s actions in the rat, including those affecting the development of the mammary apparatus. In this report, MCA1 was utilized to aid in the identification of the source of relaxin in rat milk. Treatment of lactating rats with MCA1 completely neutralized the luteal relaxin circulating in serum but did not decrease the concentration of immunoactive relaxin secreted in milk. Moreover, the antibody did not appear to reach the mammary epithelium. The evidence thus supports the view that in the rat, the relaxin secreted in milk is primarily a product of the mammary glands and not concentrated from the systemic circulation.
Deferasirox Reduces Iron Overload in a Murine Model of Juvenile Hemochromatosis
Authors: Nick Hanspeter , Allegrini Peter R. , Fozard Lucy , Junker Ursula , Rojkjaer Lisa , Salie Rishard , Niederkofler Vera , O’Reilly Terrence
Published: February 2009

Mutations in hemojuvelin (HJV) cause severe juvenile hemochromatosis, characterized by iron loading of the heart, liver, and pancreas. Knockout (KO) mice lacking HJV (Hjv−/−) spontaneously load with dietary iron and, therefore, present a model for hereditary hemochromatosis (HH). In HH, iron chelation may be considered in noncandidates for phlebotomy. We examined the effects of deferasirox, an oral chelator, in Hjv−/− mice. Hepatic, cardiac, splenic, and pancreatic iron were determined by measuring elemental iron and scoring histological sections. Heart and liver iron levels were also determined repeatedly by quantitative R2* magnetic resonance imaging (MRI). The time course of iron loading without intervention was followed from Week 8 of age (study start) to Week 20, when once-daily (5×/ week) deferasirox was administered, to Week 28. At 8 weeks, liver iron of KO mice was already markedly elevated versus wild-type mice ( P < 0.001) and reached a plateau around Week 14. In contrast, Week 8 cardiac and pancreatic iron levels were similar in both KO and wild-type mice and, compared with the liver, showed a delayed but massive iron loading up to Week 20. Contrary to the liver, heart, and pancreas, the KO mice spleen had lower iron content versus wild-type mice. In Hjv−/− mice, liver and heart iron burden was effectively reduced with deferasirox 100 mg/kg ( P < 0.05). Although deferasirox was less efficacious at this dose in the pancreas, over the observed time period, a clear trend toward reduced organ iron load was noted. There was no noticeable effect of deferasirox upon splenic iron in Hjv−/− mice. Quantitative R2* MRI demonstrated the ability to assess iron concentrations in the liver and myocardial muscle accurately and repetitively. Hepatic ( R = 0.86; P = 3.2*10− 12) and delayed myocardial ( R = 0.81; P = 2.9*10− 10) iron accumulation could be followed noninvasively with high agreement to invasive methods.
Chios Mastic Gum Extract and Isolated Phytosterol Tirucallol Exhibit Anti-Inflammatory Activity in Human Aortic Endothelial Cells
Authors: Loizou Stella , Paraschos Sotirios , Mitakou Sofia , Chrousos George P. , Lekakis Ioannis , Moutsatsou Paraskevi
Published: February 2009

Chios mastic gum (CMG) is a white, semitransparent, natural resin that is obtained as a trunk exudate from mastic trees. Triterpenic compounds and phytosterols like tirucallol are among its major components. CMG has been associated with cardiovascular protection, exerting its effect mainly through increasing the antioxidant defense system, and effectively lowering the levels of serum cholesterol in human subjects. However, data on its anti-inflammatory effect on endothelium are scarce. Attachment of leukocytes to the vascular endothelium and the subsequent migration of cells into the vessel wall are early events in atherogenesis, and this process requires the expression of endothelial adhesion molecules. In this study, we examined the effect of CMG neutral extract (25–200 μ g/ml) and tirucallol (0.1–100 μ M) on the following: 1) the expression of adhesion molecules (VCAM-1 and ICAM-1) by Cell ELISA and 2) the attachment of monocytes (U937 cells) in TNF-α stimulated Human Aortic Endothelial Cells (HAEC) by Adhesion assay. The impact of treatment with CMG neutral extract and tirucallol in NFkB phosphorylation was also examined by a cell-based ELISA kit. Both CMG extract and tirucallol inhibit significantly VCAM-1 and ICAM-1 expression in TNF-α-stimulated HAEC. They also inhibit significantly the binding of U937 cells to TNF-α-stimulated HAEC and attenuate the phosphorylation of NFkB p65. This study extends existing data regarding the cardioprotective effect of CMG, expands the spectrum of known phytosterols with potent antiatheromatic activity, provides new insight into the mechanisms underlying the beneficial effect of CMG on endothelial function, and may aid in design of new therapy for intervention in atherosclerosis.
Regulation of Epithelial-Mesenchymal Transition in Palatal Fusion
Authors: Yu Wenli , Ruest Louis-Bruno , Svoboda Kathy K. H.
Published: February 2009

During palatal fusion, the midline epithelial seam between the palatal shelves degrades to achieve mesenchymal confluence. Morphological and molecular evidence support the theory that the epithelial-mesenchymal transition is one mechanism that regulates palatal fusion. It appears that transforming growth factor (TGF)-β signaling plays a role in palatal EMT. TGFβ3 is the main inducer in palatal fusion and activates both Smad-dependent and -independent signaling pathways, including the key EMT transcription factors, Lef1, Twist, and Snail1, in the MEE prior to the palatal EMT program. The roles and interactions among these transcription factors will be discussed.
Selenium Requirements Are Higher for Glutathione Peroxidase-1 mRNA than Gpx1 Activity in Rat Testis
Authors: Schriever Sonja C. , Barnes Kimberly M. , Evenson Jacqueline K. , Raines Anna M. , Sunde Roger A.
Published: February 2009

Selenium (Se) plays a critical role in testis, sperm, and reproduction, and testis Se levels are remarkably maintained in Se deficiency. In most other tissues, Se levels decrease dramatically as do levels of most selenoproteins and levels of a subset of Se-regulated selenoprotein mRNAs. Because of the recent identification of key molecules in the targeted trafficking of Se to the testis, we examined the hierarchy of Se regulation in testis by determining the dietary Se regulation of the full testis selenoproteome in rats fed graded levels of Se (0 to 0.8 μg Se/g) as Na2SeO3for 28 d. Se status did not significantly affect testis weight or glutathione peroxidase 4 (Gpx4) activity ( P > 0.05). qRT-PCR analysis of selenoprotein mRNA expression revealed that 21 of the 24 selenoprotein mRNAs and ApoER2 mRNA (the selenoprotein P [Sepp1] receptor) were also not regulated significantly by dietary Se status. In contrast, Gpx1 activity decreased to 28% of Se-adequate levels, and mRNA levels for Gpx1, Sepp1, and Sepw1 (selenoprotein W) decreased significantly in Se-deficient rats to 45, 46, and 55%, respectively, of Se-adequate plateau levels. Overlap of hyperbolic Gpx4 activity and Sepw1 mRNA response curves with testis Se concentration, all with minimum dietary Se requirements <0.016 μg Se/g, showed the priority for synthesis of Gpx4. Higher minimum dietary Se requirements of 0.04 μg Se/g for Gpx1 activity and Sepp1 mRNA, and the even higher minimum dietary Se requirement of 0.08 μg Se/g for Gpx1 mRNA, suggest that the hierarchy of these biomarkers reflects distinct, lower priority pools, cell types, and roles for Se within the testis.
Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography
Authors: Wang Deng-Bin
Published: February 2009

Laparoscopic surgery is the main treatment method for patients with gastrointestinal malignant tumors. Although laparoscopic surgery is minimally invasive, its tool stimulation and pneumoperitoneum pressure often cause strong stress reactions in patients. On the other hand, gastrointestinal surgery can cause stronger pain in patients, compared to other surgeries. Transversus abdominis plane block (TAPB) can effectively inhibit the transmission of nerve impulses caused by surgical stimulation, alleviate patient pain, and thus alleviate stress reactions. Remazolam is an acting, safe, and effective sedative, which has little effect on hemodynamics and is suitable for most patients. TAPB combined with remazolam can reduce the dosage of total anesthetic drugs, reduce adverse reactions, reduce stress reactions, and facilitate the rapid postoperative recovery of patients.
Transcriptional activation of the Mycobacterium tuberculosis virulence‐associated small RNA MTS1338 by the response regulators DosR and PhoP
Authors: Kumar Krishan , Dutta Tanmay
Published: April 2024

MTS1338, a distinctive small RNA in pathogenic mycobacteria, plays a crucial role in host–pathogen interactions during infection. Mycobacterial cells encounter heterogeneous stresses in macrophages, which highly upregulate MTS1338. A dormancy regulatory factor DosR regulates the intracellular abundance of MTS1338. Herein, we investigated the interplay of DosR and a low pH‐inducible gene regulator PhoP binding to the MTS1338 promoter. We identified that DosR strongly binds to two regions upstream of the MTS1338 gene. The proximal region possesses a threefold higher affinity than the distal site, but the presence of both regions increased the affinity for DosR by > 10‐fold. PhoP did not bind to the MTS1338 gene but binds to the DosR‐bound MTS1338 gene, suggesting a concerted mechanism for MTS1338 expression.
Reconfigurable Logic Gates Capable of Device‐Level Parallel Processing Through Multi‐Input Synaptic Device
Authors: Roe Dong Gue , Park Sung Hyeon , Jeong Sang Young , Choi Yoon Young , Ahn Jong‐Hyun , Woo Han Young , Cho Jeong Ho
Published: April 2024

Synaptic devices have gained prominence as viable alternatives to conventional complementary metal‐oxide‐semiconductor‐based (CMOS) electronics in the information processing field owing to their inherent advantages in analog and parallel operations. The potential of synaptic devices has not yet been fully utilized for logic operations because only the conventional binary logic structure has been applied to analog synaptic devices, leading to the loss of advantages unique to analog signals. To resolve this issue, an innovative concept is proposed: an analog logic gate that can perform parallel operations at the device level and is coupled with logic reconfigurations, enabling comprehensive analog computation. This logic gate comprises two synaptic devices with different retention characteristics, adjusted by the side‐chain engineering of an organic polymer. The long‐term and short‐term synaptic devices serve as reconfigurable synapse for logic mode selection and parallel processable logic synapse, respectively. In this study, the reconfigurable and parallel processable synaptic logic circuit is effectively implemented in a personalized disease risk diagnostic system. This innovative approach not only allows for the simultaneous computation of analog‐formed diagnostic data, but also enhances both computing efficiency and system complexity in general synaptic systems.
Design Principles of Diketopyrrolopyrrole‐Thienopyrrolodione Acceptor1–Acceptor2 Copolymers
Authors: Erhardt Andreas , Hungenberg Julian , Chantler Paul , Kuhn Meike , Huynh Thanh Tung , Hochgesang Adrian , Goel Mahima , Müller Christian J. , Roychoudhury Subhayan , Thomsen Lars , Medhekar Nikhil V. , Herzig Eva M. , Prendergast David , Thelakkat Mukundan , McNeill Christopher R.
Published: April 2024

The design principles of acceptor1–acceptor2 copolymers featuring alternating diketopyrrolopyrrole (DPP) and thienopyrrolodione (TPD) moieties are investigated. The investigated series of polymers is obtained by varying the aromatic linker between the two acceptor motifs between thiophene, thiazole, pyridine, and benzene. High electron affinities between 3.96 and 4.42 eV, facilitated by the synergy of the acceptor motifs are determined with optical gaps between 1.37 and 2.02 eV. Grazing incidence wide‐angle X‐ray scattering studies reveal a range of film morphologies after thermal annealing, including face‐on, end‐on and superstructure edge‐on‐like crystallites. Conversely, all materials form thin edge‐on layers on the polymer–air interface, as demonstrated by multi‐elemental near‐edge X‐ray absorption fine‐structure spectroscopy. The benefit of the electron‐deficient linkers thiazole and pyridine is evident: In organic field effect transistors, electron mobilities of up to 4.6 × 10−2 cm2 V−1 s−1 are obtained with outstanding on/off current ratios of 5 × 105, facilitated by the absence of detectable hole transport in these materials. Viability for all‐polymer solar cells is assessed in active layer blends with the donor polymer PM6, yielding a maximum average power conversion efficiency of 4.8% and an open circuit voltage above 1 V.
Te nanomesh/black‐Si van der Waals Heterostructure for High‐Performance Photodetector
Authors: Wei Yiyang , Lan Changyong , Zeng Ji , Meng You , Zhou Shuren , Yip SenPo , Li Chun , Yin Yi , Ho Johnny C.
Published: April 2024

Van der Waals (vdW) heterostructures have gained significant attention in photodetectors due to their seamless integration with materials possessing diverse functionalities. In this study, the fabrication of a Te nanomesh/black‐Si vdW heterostructure is presented, and investigated its photoresponse properties. The heterostructure exhibits a pronounced rectification behavior, characterized by a rectification ratio of 2.2 × 104. Notably, the heterostructure device demonstrates commendable photoresponse properties, including a high responsivity of 350 mA W−1, an extensive linear dynamic range of 45.5 dB, a high specific detectivity of 9.6 × 1011 Jones, and a wide spectral response ranging from 400 to 1550 nm. Furthermore, the heterostructure exhibits rapid response, with a rise time and a decay time of 70 and 140 µs, respectively. These exceptional photoresponse properties can be attributed to the robust internal built‐in electrical field at the hetero‐interface and the augmented light absorption in black‐Si. The outstanding photoresponse properties of the heterostructure make it a promising candidate for multiwavelength single‐pixel imaging, enabling the collection of mask patterns under varying wavelengths of light radiation. This work provides a novel approach for fabricating mixed‐dimensional vdW heterostructures, offering promising prospects for advancements in optoelectronics.
Homogeneous and Significant Near‐Field Enhancement in All‐Dielectric Metasurfaces for Sensing Applications
Authors: Li Guangyuan , Liu Yunhui
Published: April 2024

All‐dielectric metasurfaces supporting high‐Q resonances have emerged as a promising platform for sensing applications. However, the greatly enhanced near‐fields are usually confined within the all‐dielectric nanostructures rather than the outside analyte region, severely limiting the bulk sensitivity and the biosensing performance. Here, a silicon metasurface formed by the hybridization of two lattices with a relative displacement is designed to support nonlocal quasi‐bound states in the continuum (q‐BICs) featuring homogeneous and significant near‐field enhancement over large volumes outside the silicon nanodisks. A high bulk sensitivity of 407 nm RIU–1 is experimentally demonstrated for the refractive index sensing applications, and a limit of detection down to 20 pg mL–1 for a protein biomarker for the early‐stage breast cancer screening, which is improved by more than an order of magnitude over the state of the art. It is expected that the nonlocal q‐BICs open new opportunities for realizing greatly enhanced light–matter interactions over large volumes in applications beyond biochemical sensing.
Fabrication of Translucent and Chemically Durable Crystal‐Glass Composite with Multicolor Persistent Luminescence
Authors: Mohamed Moushira. A. , Ali Mohamed. A. , Shaorun Guo , Liu Xiaofeng , Qiu Jianrong
Published: April 2024

Long persistent luminescence materials (LPLMs) are promising candidates for various photonic applications, owing to their ability to store light. In spite of advancements in exploring of new LPLMs, the fabrication of transparent centimeter‐sized LPLMs with pre‐designed shapes, high productivity, long afterglow multicolor luminescence, and high chemical stability, is still challenging. Here, high‐throughput manufacture of translucent crystal‐glass composites via a classical injection molding (IM) technique is demonstrated, in which persistent phosphors (PPs)‐amorphous silica nanoparticles‐polymer composites are molded into different shapes then thermally treated at elevated temperatures to obtain glass composites with embedded PP particles and customized shapes. The structural characterizations endorse that the PP particles are preserved during high temperature sintering, and the resultant crystal‐glass composites combine the unique benefits of both PPs and silica glass. Remarkably, the total production time to manufacture 100 pieces of centimeter‐sized crystal‐glass composites is 35 h, thus enabling high‐throughput production of glass composite articles by the IM method. In addition, the injection molded crystal‐glass composites demonstrate long afterglow multicolor luminescence and ultrahigh chemical durability. This study provides a massive production strategy for the fabrication of translucent and stable multicolor persistent luminescent objects with customized shapes, which can be used in numerous applications.
Access to Benzyl Oxindoles via Electron Donor‐Acceptor Complex Photoactivation Using Thianthrenium Salts and Potassium Carbonate
Authors: Sarró Pau , Gallego‐Gamo Albert , Pleixats Roser , Vallribera Adelina , Gimbert‐Suriñach Carolina , Granados Albert
Published: April 2024

A photochemical synthesis of biologically relevant benzyl oxindoles is presented via electron‐donor acceptor (EDA) complex strategy. This exogenous photocatalyst‐free method describes the formation of a new electron donor‐acceptor complex based on potassium carbonate and thianthrenium salts for C(sp2)−C(sp3) bond formation. This transition‐metal free reaction allows a rapid increase in oxindoles molecular complexity chemical space, tolerating different functional groups as well as sophisticated biomolecules. The scalability and sustainability of this method is highlighted by an important waste recovery protocol. Mechanistic investigations support the formation of an EDA complex that induces a radical chain, and the applicability of this method is showcased by straightforward derivatization reactions.
NIR‐II Fluorescence Sensor Based on Steric Hindrance Regulated Molecular Packing for In Vivo Epilepsy Visualization
Authors: Zhao Mengyao , Lai Weiping , Li Benhao , Bai Tianwen , Liu Chunyan , Lin Yanfei , An Shixuan , Guo Longhua , Li Lei , Wang Jianbo , Zhang Fan
Published: April 2024

Fluorescence sensing is crucial to studying biological processes and diagnosing diseases, especially in the second near‐infrared (NIR‐II) window with reduced background signals. However, it's still a great challenge to construct “off‐on” sensors when the sensing wavelength extends into the NIR‐II region to obtain higher imaging contrast, mainly due to the difficult synthesis of spectral overlapped quencher. Here, we present a new fluorescence quenching strategy, which utilizes steric hindrance quencher (SHQ) to tune the molecular packing state of fluorophores and suppress the emission signal. Density functional theory (DFT) calculations further reveal that large SHQs can competitively pack with fluorophores and prevent their self‐aggregation. Based on this quenching mechanism, a novel activatable “off‐on” sensing method is achieved via bio‐analyte responsive invalidation of SHQ, namely the Steric Hindrance Invalidation geNerated Emission (SHINE) strategy. As a proof of concept, the ClO−‐sensitive SHQ lead to the bright NIR‐II signal release in epileptic mouse hippocampus under the skull and high photon scattering brain tissue, providing the real‐time visualization of ClO− generation process in living epileptic mice.
Reaction Environment Regulation for Electrocatalytic CO2 Reduction in Acids
Authors: Zeng Min , Fang Wensheng , Cen Yiren , Zhang Xinyi , Hu Yongming , Xia Bao Yu
Published: April 2024

The electrocatalytic CO2 reduction reaction (CO2RR) is a sustainable route for converting CO2 into value‐added fuels and feedstocks, advancing a carbon‐neutral economy. The electrolyte critically influences CO2 utilization, reaction rate and product selectivity. While typically conducted in neutral/alkaline aqueous electrolytes, the CO2RR faces challenges due to (bi)carbonate formation and its crossover to the anolyte, reducing efficiency and stability. Acidic media offer promise by suppressing these processes, but the low Faradaic efficiency, especially for multicarbon (C2+) products, and poor electrocatalyst stability persist. The effective regulation of the reaction environment at the cathode is essential to favor the CO2RR over the competitive hydrogen evolution reaction (HER) and improve long‐term stability. This review examines progress in the acidic CO2RR, focusing on reaction environment regulation strategies such as electrocatalyst design, electrode modification and electrolyte engineering to promote the CO2RR. Insights into the reaction mechanisms via in situ/operando techniques and theoretical calculations are discussed, along with critical challenges and future directions in acidic CO2RR technology, offering guidance for developing practical systems for the carbon‐neutral community.
Synthesis and evaluation of PVC‐Cu/Al2O3 nanocomposite membranes for removing of natural organic matter from the wastewater
Authors: Sajjadi Seyed Mehdi , Etemadi Habib , Zaremanesh Masoumeh
Published: April 2024

The synthesis of Cu/Al2O3 nanoparticles (NPs) was conducted by the citric acid sol–gel technique. We used the synthesized NPs to enhance PVC membranes and create PVC‐Cu/Al2O3 nanocomposite membranes. The quantities of NPs utilized were 0, 0.5, 1, 1.5, and 2 wt.% of solid phase. The point of this study was to look into how PVC‐Cu/Al2O3 membranes can be used to remove natural organic matter (NOM) from polluted water in submerged membrane systems. The membranes treated with NPs exhibited increased porosity, improved hydrophilicity, and smoother surface. Results revealed that the incorporation of 1 wt.% NPs into PVC (PVC‐CA1) demonstrated the highest degree of hydrophilicity and porosity. Moreover, PVC‐CA1 exhibited an increased number of pores, with larger pores present on the top surface and larger macrovoids on the cross‐sectional surface. The PVC‐CA1 exhibited the highest flux recovery ratio (FRR) and highest rejection rate for HA, with values of 82.6% and 92.6%, respectively. PVC‐CA1, which had an irreversible fouling ratio (IFR) of 17.3%, demonstrated the greatest resistance to fouling. Generally, incorporation of NPs into PVC resulted in increased hydrophilicity, enhanced porosity, uniform dispersion, smoother surface characteristics, and consequently improved antifouling properties. Furthermore, among the fabricated membranes, PVC‐CA1 had the most favorable antifouling performance.
Sea turtle bycatch in Argentina: A qualitative assessment in commercial vessels
Authors: Jones Sofía , Calvo Rodrigo , Rolón Melisa Celia Jazmin , Tettamanti Germán , Vera David Gustavo , Prosdocimi Laura
Published: April 2024

1. The Northern Argentine continental shelf is a sea turtle feeding ground that overlaps with important fisheries. Few studies assessed bycatch impact, especially on commercial vessels. 2. This work documents sea turtles' bycatch, fishery involved, species captured and crew actions. 3. Bycatch in four fisheries were registered at the 107 interviews to fishers conducted between 2021 and 2023, showing the urgency to research bottom trawling for demersal multi‐species. Fishers frequently recognize Caretta caretta, and positive and negative practices towards animals have been documented on‐board. 4. These results will help focus researches on fisheries with the greatest impact on sea turtles in the region. They also underscore the necessity for implementing commercial vessel monitoring programmes and improving on‐board handling practices.
Ehren und Erinnern (re‐)konstruieren – ein Kommentar.
Authors: Pinwinkler Alexander
Published: April 2024

The commentary interprets the practices of remembering and the creation of memory as an attempt at academic and public‐media self‐understanding, which exhibit past‐political, present‐oriented and future‐oriented perspectives and intentions. Academic politics of history and remembrance can hardly be imagined without reference to and interaction with the public and politics. The contributions in this special issue make it clear that a large number of public and private actors and interest groups are usually involved in memory policy controversies surrounding academics. When discussing prizes, street names or school names named after academics, for example, very different logics and ideas about remembering and memory often clash. This fundamental dilemma is particularly evident in debates about controversial academics who worked before, during and after the Nazi era.
Meeting the closed‐loop challenge: The “Who‐What‐How” strategic choices for a successful remanufacturing approach
Authors: Pesce Danilo , Franzè Claudia , Paolucci Emilio
Published: April 2024

Remanufacturing is a life‐cycle renewal process recognised as one of the most effective circular strategies that can be adopted to achieve sustainable production. However, its potential has been hindered by the absence of an integrated perspective across various business domains to catalyse successful remanufacturing efforts. This paper aims to explore how such an integrated perspective can facilitate the creation of sustainable value within remanufacturing business models. To fill this gap, an in‐depth longitudinal case study was conducted on how remanufacturing practices can be effectively implemented in the white goods sector. The research identifies four fundamental mechanisms that, when used synergistically, pave the way for a successful remanufacturing approach yielding triple‐bottom‐line benefits. The study contributes to the remanufacturing literature by illustrating how (i) moving from products to solutions that fulfil customer priorities, (ii) resequencing business processes according to customer‐oriented logic, (iii) enhancing the clock‐speed of decision‐making and (iv) sharing risks within the supply chain, can unveil new strategic positioning for sustainable value creation. From a practical perspective, it advocates for the adept management of remanufacturing uncertainties through continuous, active questioning of “Who‐What‐How” choices and the cultivation of circular and organic interdependencies.
Role of extracellular vesicles in insulin resistance: Signaling pathways, bioactive substances, miRNAs, and therapeutic potential
Authors: Zhang Wang , Song Mengdi , Fang Zhou , Chen Feng , Yuan Hui , Gao Xinran , Liu Kehai
Published: April 2024

Extracellular vesicles are small lipid bilayer particles that resemble the structure of cells and range in size from 30 to 1000 nm. They transport a variety of physiologically active molecules, such as proteins, lipids, and miRNAs. Insulin resistance (IR) is a pathological disease in which insulin‐responsive organs or components become less sensitive to insulin's physiological effects, resulting in decreased glucose metabolism in target organs such as the liver, muscle, and adipose tissue. Extracellular vesicles have received a lot of attention as essential intercellular communication mediators in the setting of IR. This review looks at extracellular vesicles' role in IR from three angles: signaling pathways, bioactive compounds, and miRNAs. Relevant publications are gathered to investigate the induction, inhibition, and bidirectional regulation of extracellular vesicles in IR, as well as their role in insulin‐related illnesses. Furthermore, considering the critical function of extracellular vesicles in regulating IR, the study analyzes the practicality of employing extracellular vesicles for medication delivery and the promise of combination therapy for IR.