Development and characterization of 3D-printed electroconductive pHEMA-co-MAA NP-laden hydrogels for tissue engineering

Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration.In this study,we developed a poly(2-hydroxyethyl methacrylate-co-methacrylic acid)(pHEMA-co-MAA)based hydrogel loaded with newly synthesized conductive poly(3,4-ethylene-dioxythiophene)(PEDOT)and polypyrrole(PPy)nanoparticles(NPs),and subsequently processed these hydrogels into tissue engineered constructs via three-dimensional(3D)printing.The presence of the NPs was critical as they altered the rheological properties during printing.However,all samples exhibited suitable shear thinning properties,allowing for the development of an optimized processing window for 3D printing.Samples were 3D printed into pre-determined disk-shaped configurations of 2 and 10 mm in height and diameter,respectively.We observed that the NPs disrupted the gel crosslinking efficiencies,leading to shorter degradation times and compressive mechanical properties ranging between 450 and 550 kPa.The conductivity of the printed hydrogels increased along with the NP concentration to(5.10±0.37)×10^(−7)S/cm.In vitro studies with cortical astrocyte cell cultures demonstrated that exposure to the pHEMA-co-MAA NP hydrogels yielded high cellular viability and proliferation rates.Finally,hydrogel antimicrobial studies with staphylococcus epidermidis bacteria revealed that the developed hydrogels affected bacterial growth.Taken together,these materials show promise for various TE strategies.

Challenges and opportunities in the production of magnesium parts by directed energy deposition processes

Mg-alloys have gained considerable attention in recent years for their outstanding properties such as lightweight,high specific strength,and corrosion resistance,making them attractive for applications in medical,aerospace,automotive,and other transport industries.However,their widespread application is hindered by their low formability at room temperature due to limited slip systems.Cast Mg-alloys have low mechanical properties due to the presence of casting defects such as porosity and anisotropy in addition to the high scrap.While casting methods benefit from established process optimization techniques for these problems,additive manufacturing methods are increasingly replacing casting methods in Mg alloys as they provide more precise control over the microstructure and allow specific grain orientations,potentially enabling easier optimization of anisotropy properties in certain applications.Although metal additive manufacturing(MAM)technology also results in some manufacturing defects such as inhomogeneous microstructural evolution and porosity and additively manufactured Mg alloy parts exhibit lower properties than the wrought parts,they in general exhibit superior properties than the cast counterparts.Thus,MAM is a promising technique to produce Mg alloy parts.Directed energy deposition processes,particularly wire arc directed energy deposition(WA-DED),have emerged as an advantageous additive manufacturing(AM)technique for metallic materials including magnesium alloys,offering advantages such as high deposition rates,improved material efficiency,and reduced production costs compared to subtractive processes.However,the inherent challenges associated with magnesium,such as its high reactivity and susceptibility to oxidation,pose unique hurdles in the application of this technology.This review paper delves into the progress made in the application of DED technology to Mg-alloys,its challenges,and prospects.Furthermore,the predominant imperfections,notably inhomogeneous microstructure evolution and porosity,observed in Mg-alloy components manufactured through DED are discussed.Additionally,the preventive measures implemented to counteract the formation of these defects are explored.

Drought Tolerance and Recovery of the Sedge Carex planostachys (Cyperaceae) from Central Texas Woodlands

Carex planostachys Kunze (Cyperaceae, Cedar sedge) is an herbaceous species in a genus commonly inhabiting mesic or hydric habitats. Carex planostachys is found in arid and semi-arid Juniperus woodlands. Arid conditions impose survival challenges to plants in dry areas. Some plants have plasticity responses to soil water content and continued normal though reduced functions through droughts, but most herbaceous plants do not survive. Limited previous studies have suggested C. planostachys is tolerant of drought. Physiological responses of C. planostachys from Juniperus woodlands was examined is this study to determine how long plants could survive without water and if they are capable of recovery from very negative water potentials beyond what is considered the permanent wilting point for most herbaceous plants. Plants were placed in pots in partial shade in this experiment. Water loss from the soil with plants was an inverse 2nd order polynomial function with soil water decreasing from 32% to 8% by day 28 of the study. Leaf water potential was also an inverse 2nd order polynomial function but did not decline significantly until 14 days without watering. Leaf water potential was −10.0 MPa after 35 days without watering. Non-watered plants Anet, (photosynthetic rate) was significantly lower compared to the water treatment by day 21 as was stomatal conductance and transpiration. When non-watered plants were watered after 21, 28 or 35 days, full recovery of physiological responses occurred within 7 days. The length of time that C. planostachys was able to withstand drought was greater than the annual trends in lack of precipitation during springtime in this area. Carex planostachys can photosynthesize at water stress between −8 and −10 MPa. Carex planostachys drought and shade tolerance enables it to occupy an understory niche devoid of other herbaceous plants.

The ability of biostimulants and copper-containing fungicide to protect cotton against chilling stress

Background Cotton(Gossypium hirsutum L.),adapted to tropical and subtropical regions of the world,is highly sensitive to low temperatures throughout its life cycle.The objective of this study was to evaluate the mitigating effects of different doses of animal-derived(0.25%,0.50%,and 1.00% Isabion■),seaweed-based(0.165%,0.330%,and 0.660% Proton■)biostimulants,as well as a copper(Cu)-containing fungicide application,on cotton cultivar Lazer seedlings at the four true leaves(V4)stage.The plants were exposed to a low temperature of 5℃for 48 h,and the changes in morphological(seedling fresh and dry weight,plant height,and stem diameter)and physiological parameters(leaf temperature,chlorophyll content,relative water content,electrolyte leakage,and relative injury)were examined.Results The results revealed that chilling stress reduced plant growth,while biostimulants helped protect the plants and overcome the adverse effects of chilling.Under chilling stress,there was a considerable reduction in seedling fresh weight(SFW),seedling dry weight(SDW),plant height(PH),stem diameter(SD),leaf temperature(LT),and relative water content(RWC).Cotton seedlings treated with the animal-derived biostimulants showed significantly enhanced SFW,SDW,PH,SD,LT,chlorophyll content(Chl),electrolyte leakage(EL),and relative injury(RI),although there were no positive changes in RWC.No significant differences in the morphological traits were observed among the doses of seaweed biostimulants.For SDW,PH,EL,and RI,the best results were obtained with the application of a fungicide containing copper.Conclusion These results show the efficiency of the biostimulant and fungicide treatments in mitigating low-temperature stress in cotton seedlings.Applying a copper-containing fungicide to cotton seedlings helped to counteract the negative effects of low-temperature stress and to protect the plants from damage by maintaining electrolyte balance.Among the biostimulant applications,all levels of animal-derived biostimulant applications,as well as the 0.660% level of the seaweed-derived biostimulant,led to increased tolerance of cotton plants to chilling stress.

RETRACTED: Determination of the Mesalazine Solubility at Biorelevant Temperature

Short Retraction NoticeThis article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused. The full retraction notice in PDF is preceding the original paper, which is marked "RETRACTED".

Combined Effect of Nutrient and Pest Management on Soil Ecological Quality in Hybrid Rice Double-Cropping System

The mineral fertilizers (NPK) and pesticide, including herbicides, insecticides and fungicides, were applied alone or in combination and the soil sampling was done at different growth stages during the crop cycle to study the changes in soil organic matter, microbial biomass and their activity parameters in a paddy soil with different nutrient and pest management practices in a hybrid rice double-cropping system. A consistent increase in the electron transport system (ETS) activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or with pesticides increased ETS activity, while a decline of ETS activity was noticed with pesticides alone as compared with the control. Nearly an increasing trend in soil phenol content was observed with the progression of crop growth stages, while the usage of pesticides alone caused maximum increments in the soil phenol content. The soil protein content was found nearly stable with fertilizers and/or pesticides application at various growth stages in both crops taken. But notable changes were noticed at different growth stages probably because of fluctuations in moisture and temperature at particular stages, which might have their effects on N mineralization. Marked depletions in the phospholipid content were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also produced slight changes, in which a higher decline was noticed with pesticide application alone compared with the control.

Possible markers of the Jurassic/Cretaceous boundary in the Mediterranean Tethys:A review and state of art

During the last decades,several integrated studies of Tethyan Jurassic/Cretaceous boundary sections from different countries were published with the objective to indicate problems for the selection of biological,chemical or physical markers suitable for identification of the Jurassic/Cretaceous boundary-the only system boundary within the Phanerozoic still not fixed by GSSP.Drawing the boundary between the Jurassic and Cretaceous systems is a matter of global scale discussions.The problem of proposing possible J/K boundary stratotypes results from lack of a global index fossils, global sea level drop,paleogeographic changes causing development of isolated facies areas,as well as from the effect of Late Cimmerian Orogeny.This contribution summarizes and comments data on J/K boundary interval obtained from several important Tethyan sections and shows still existing problems and discrepancies in its determination.

A New Thorny Lacewing (Insecta:Neuroptera:Rhachiberothidae) from the Early Cretaceous Amber of Lebanon

A new genus and species of Rhachiberothidae, Raptorapax terribilissima gen. et sp. nov. from the Cretaceous amber of Lebanon is described. The new genus is assigned to the subfamily Paraberothinae. The new material confirms the great diversity of the group in the Cretaceous age and its decrease in diversity in recent times.

First Psocodean (Psocodea,Empheriidae) from the Cretaceous Amber of New Jersey

Representatives of the extinct psocid family Empheriidae are known from Eocene Baltic amber, Lowermost Eocene French amber （Oise）, and Lower Cretaceous Spanish amber （Alava）. We report herein the first discovery of an empheriid psocid from the Cretaceous amber of New Jersey as Jerseyempheria grimaldii gen. et sp. nov. The fossil is figured and described. The new species is distinguished from related taxa. A discussion and checklist of Empheriidae are provided.

Effects of Central Administration of Glutamine and Alanine on Feed Intake and Hypothalamic Expression of Orexigenic and Anorexigenic Neuropetides in Broiler Chicks

Different amino acids have been shown to affect feed intake when injected directly into the central nervous system of birds. In the present study, we investigated the effects of L-glutamine and L-alanine on feed intake and the mRNA expression levels of hypothalamic neuropeptides involved in feed intake regulation in broiler chicks. L-Glutamine or L- alanine was intra-cerebroventricularly （ICV） administered to 4-d-old broiler chicks and the feed intake were recorded at various time points. Quantitative PCR was performed to determine the hypothalamic mRNA expression levels of neuropeptide Y （NPY）, agouti related protein （AgRP）, pro-opiomelanocortin （POMC）, melanocortin receptor 4 （MC4R） and corticotropin releasing factor （CRF）. Our results showed that ICV administration of L-glutamine （0.55 or 5.5 pmol） significantly increased feed intake up to 2 h post-administration period and the hypothalamic NPY mRNA expression levels, while it markedly decreased hypothalamic POMC and CRF mRNA expression levels. In contrast, ICV administration of L-alanine （4 lamol） significantly decreased feed intake for the first 0.5 h post-administration period, and reduced the hypothalamic AgRP mRNA expression levels, while it remarkablely enhanced the mRNA expression levels of MC4R and CRF. These findings suggested that L-glutamine and L-alanine could act within the hypothalamus to influence feed intake in broiler chicks, and that both orexigenic and anorexigenic neuropeptide genes might contribute directly to these effects.

Effects of “Bioactive” amino acids leucine, glutamate, arginine and tryptophan on feed intake and mRNA expression of relative neuropeptides in broiler chicks

Feed intake control is vital to ensuring optimal nutrition and achieving full potential for growth and development in poultry. The aim of the present study was to investigate the effects of L-leucine, L-glutamate, L-tryptophan and L-arginine on feed intake and the mRNA expression levels of hypothalamic Neuropeptide involved in feed intake regulation in broiler chicks. Leucine, glutamate, tryptophan or arginine was intra-cerebroventricularly （ICV） administrated to 4d-old broiler chicks respectively and the feed intake were recorded at various time points. Quantitative PCR was performed to determine the hypothalamic mRNA expression levels of Neuropeptide Y （NPY）, agouti related protein （AgRP）, pro-opiomelanocortin （POMC）, melanocortin receptor 4 （MC4R） and corticotrophin releasing factor （CRF）. Our results showed that ICV administration of L-leucine （0.15 or 1.5 μmol） significantly （P〈0.05） increased feed intake up to 2 h post-administration period and elevated both hypothalamic NPY and AgRP mRNA expression levels. In contrast, ICV administration of L-glutamate （1.6 μmol） significantly （P 〈 0.05） decreased feed intake 0.25, 0.5 and 2 h post-injection, and increased hypothalamic CRF and MC4R mRNA expression levels. Meanwhile, both L-tryptophan （10 or 100 μg） and L-arginine （20 or 200 μg） had no significant effect on feed intake. These findings suggested that L-leucine and L-glutamate could act within the hypothalamus to influence food intake, and that both orexigenic and anorexigenic Neuropeptide genes might contribute directly to these effects.

Assessment of Reusing Ferrochrome Slag Wastes in Mortar as SCMs

The demand for alternative cementitious materials is on the rise,as the cement causes huge energy consumption and produces greenhouse gas emission.Additionally,there is economic potential for the construction industry to reuse wastes as supplementary building materials.The purpose of this study is to evaluate the potential of utilizing ferrochrome slag wastes in mortar as supplementary cementitious materials (SCMs),thereby achieving this double-sided goal.Thus,the mechanical and physical properties of ferrochrome slag wastes were investigated to be used as admixtures in concrete production.Three different cement mortar specimens were prepared by replacing cement with ferrochrome slag in ratios of 0,30%,and 60% by mass and flexural and compressive strengths of the specimens were determined at the ages of 7,28,56,90,and 180 days.Also,the effects of the ferrochrome slag replacement ratio on workability,setting time and volume expansion were revealed.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were also investigated to study the microstructural properties of the specimens containing ferrochrome slag.Based on the results,it is concluded that ferrochrome slag wastes have pozzolanic activity,therefore reusing them as SCMs in the cement and concrete industry is convenient.

Surface Geophysical Methods used to Verify the Karst Geological Structure in the Built-up Area:A Case Study of Specific Engineering-Geological Conditions

This article presents a research study of complex limestone karst engineering-geological conditions in the municipality Valaskanear Banska Bystrica in Slovakia.The aim of the study is to demonstrate the impossibility of spatial identification of cave spaces using surface geophysical methods due to the specific engineering-geological conditions of a thick surface layer of anthropogenic fill containing highly heterogeneous anthropogenic material.Its maximum thickness is 3 m.Another specificific condition of the study area is its location in the built-up area,due to which the applicability of geophysical methods was limited.The article contains methodological recommendations to be used in analogous geological conditions with karst structures topped with anthropogenic fill,which complicates the identification of cave spaces.The recommended solution herein is the identification of the cave system using underground mapping of the karst and its projection onto the surface for which surface geophysical methods have been combined.

Antibacterial mechanism with consequent cytotoxicity of different reinforcements in biodegradable magnesium and zinc alloys: A review

Benefits achieved by the biodegradable magnesium(Mg) and zinc(Zn) implants could be suppressed due to the invasion of infectious microbial, common bacteria, and fungi. Postoperative medications and the antibacterial properties of pure Mg and Zn are insufficient against biofilm and antibiotic-resistant bacteria, bringing osteomyelitis, necrosis, and even death. This study evaluates the antibacterial performance of biodegradable Mg and Zn alloys of different reinforcements, including silver(Ag), copper(Cu), lithium(Li), and gallium(Ga). Copper ions(Cu^(2+)) can eradicate biofilms and antibiotic-resistant bacteria by extracting electrons from the cellular structure. Silver ion(Ag^(+)) kills bacteria by creating bonds with the thiol group. Gallium ion(Ga^(3+)) inhibits ferric ion(Fe^(3+)) absorption, leading to nutrient deficiency and bacterial death. Nanoparticles and reactive oxygen species(ROS) can penetrate bacteria cell walls directly, develop bonds with receptors, and damage nucleotides. Antibacterial action depends on the alkali nature of metal ions and their degradation rate, which often causes cytotoxicity in living cells. Therefore, this review emphasizes the insight into degradation rate, antibacterial mechanism, and their consequent cytotoxicity and observes the correlation between antibacterial performance and oxidation number of metal ions.

Selected Adsorbents for Removal of Contaminants from Wastewater: Towards Engineering Clay Minerals

The provision and demand for safe water continues to be a major aspect for governments worldwide as the population continues to grow accompanied by an increase in anthropogenic activities that contaminate water bodies. The common contaminants are the negatively charged ions such as sulfates, positive ions like heavy metals and organic molecules like dyes and phenols. Although, various methods exist for purification of wastewater, the adsorption process is a low cost method that uses readily available adsorbents. Activated carbon, although costly for developing countries, is still the most efficient adsorbent for a variety of substances. However, low cost adsorbents derived from biowaste have being actively explored in water purification. Photocatalytic nanostructured adsorbents not only play a bifunctional role in adsorbing contaminants but also are able to decompose organic pollutants in water using sunlight. The engineering of naturally abundant clay in most developing countries offers an even inexpensive way to clean-up wastewater.

Recent advances on study of hadrosaurid dinosaurs in Heilongjiang(Amur) River area between China and Russia

Four main dinosaur-bearing sites have been investigated in latest Cretaceous deposits from the Amur/Heilongjiang Region ： Jiayin and Wulaga in China （ Yuliangze Formation）, Blagoveschensk and Kundur in Russia （Udurchukan Formation）. More than 90% of the bones discovered in these localities belong to hollow-crested lambeosaurine hadrosaurids： Charonosaurus fiayinensis at Jiayin, Amurosaurus riabinini at Blagoveschensk, Olorotitan arharensis at Kundur, and Sahaliyania elunchunorum at Wulaga. Flat-headed hadrosaurine hadrosaurids are much less numerous, but appear well diversified as well： Kerberosaurus manakini at Blagoveschensk, Wulagasaurus dongi at Wulaga, and a new genus at Kundur. Theropods are represented by shed teeth and isolated bones; isolated scutes and teeth discovered at Kundur are tentatively attributed to nodosaurids. Palynological studies suggest that these sites are probably synchronous with the Lancian＇ vertebrate localities of western North America, which represent the youngest dinosaur faunas in this area. However, the latest Cretaceous dinosaur assemblages are completely different in the Amur/Heilongjiang region （lambeosaurines abundant, ceratopsids absent） and in western North America （ceratopsids abundant, lainbeosaurines extremely rare or absent）. This probably reflects some kind of geographical barrier between both areas by Maastrichtian time rather than strong differences in palaeoecological conditions.

鲁米诺/氨基磺酸电化学发光及其多巴胺检测应用

在本文中,我们首次观察到氨基磺酸可以显著增强鲁米诺电化学发光,而且鲁米诺电化学发光的强度随着氨基磺酸浓度在0.1μmol·L^(-1)至500μmol·L^(-1)范围增加而线性增加。同时,我们观察到多巴胺可以显著猝灭鲁米诺-氨基磺酸电化学发光。基于该猝灭现象,我们建立了多巴胺的电化学发光分析方法,该方法的线性范围为0.5至20μmol·L^(-1),检出限为30 nmol·L^(-1)。该方法具有较好的选择性,尿酸、抗坏血酸、糖和一些氨基酸对电化学发光影响较小。采用标准加入法,成功地将鲁米诺-氨基磺酸体系用于尿液中多巴胺的电化学发光测定,回收率为103%~105%。另外,我们还考察了多巴胺的猝灭机理,并用Stern-Volmer方程计算了的动态猝灭常数。

Tor topography in Giresun mountains,Türkiye

Tors are mound-like rock landforms,resistant to erosion,that may sometimes reach the size of several storeys of house by volume.They may develop in different climate regions and different rock types,led by granitic rocks.In this study,tors developed in granitic rocks around Yaylal?village linked to Kürtün county in Gümü?hane were investigated.The study area is located in the eastern part of the Giresun mountain range in northeastern Turkey,2000-2300 m above sea level.The aim of the study is to determine the natural environmental characteristics in tor formation and to reveal the effect of bedrock on tor formation.During field studies,18 tors were selected by noting location,size and structural features,and dimensions were measured.Thin sections were first made from the rock samples taken from the tors and then the mineralogical composition was investigated by modal analysis method.As a result of this analysis,it was determined that the bedrock forming the tors is granite.During the field observations,it was determined that the intersecting vertical joints supported the formation of castle-like tors,while the horizontal joints supported the formation of pita pileshaped tors.There are also pseudokarstic shapes resembling kamenitza and karst pavement.In conclusion,joint sets causing local resistance differences directed the formation of tors,while excess slope affected surface erosion and suitability of climate conditions-controlled weathering rate.

Relating models of activity metabolism to the metabolic efficiency of steady swimming

Power-law ( ) and exponential power-law ( ) functional forms model activity metabolism ( ) for fully submerged swimming animals, and are special cases of the power-law polynomial equation, in which?? is the observed total metabolic rate measured at an observed steady swimming speed,? . The relationship between the metabolic efficiency of steady swimming and the exponents of?? is addressed in this paper to establish the use of?? () and?? () as optimal efficiencies for comparing the hydrodynamic and muscle metabolic efficiencies among fully submerged animals that engage in steady swimming activities. The metabolic efficiency of steady swimming is transformed into its ideal form ( ) from which??? the optimal hydrodynamic efficiency ( ) and the optimal muscle metabolic efficiency ( ) are derived. These optimal efficiencies are therefore ideal metabolic efficiencies measured at different optimal steady speeds. Subsequently, linear ( ) and exponential ( ) models are approximations with divergent optimal muscle metabolic efficiencies ( and , respectively), but with a similar optimal hydrodynamic efficiency ( ).

Persistence of herpetofauna in the urbanized rouge river ecosystem

Over 100 years, urbanization has taken place along the Rouge River watershed of southeast Michigan, USA. To determine the impact(s) of urbanization on herpetofauna, species richness and distribution in 122 wetlands along 13.0 km of the urbanized Rouge River watershed were monitored from early spring to late fall 2003. Data were mapped using Geographic Information Systems (GIS). Both amphibian and reptile species richness were associated with wetland size and hydroperiod. The invasive plants Alliaria petiolata and Rhamnus cathartica were coincident with lower than average amphibian species richness. In spite of the number of herpetofauna being relatively low, this study identified hydroperiod and wetland size as important features that may contribute to amphibian and reptile species sustainability in this highly disturbed and fragmented urban landscape.