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1.
BMC Musculoskelet Disord ; 25(1): 284, 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38609889

ABSTRACT

BACKGROUND: The purpose of the study was to assess and compare the clinical efficacy of bone transport with either circular or unilateral external fixators over an intramedullary nail in the treatment of tibial bone defects caused by infection. METHODS: Between May 2010 and January 2019, clinical and radiographic data were collected and analyzed for patients with bone defects caused by infection. Thirteen patients underwent bone transport using a unilateral external fixator over an intramedullary nail (Group A), while 12 patients were treated with a circular external fixator over an intramedullary nail (Group B). The bone and functional outcomes of both groups were assessed and compared using the Association for the Study and Application of the Method of the Ilizarov criteria, and postoperative complications were evaluated according to the Paley classification. RESULTS: A total of 25 patients were successfully treated with bone transport using external fixators over an intramedullary nail, with a mean follow-up time of 31.63 ± 5.88 months. There were no significant statistical differences in age, gender, previous surgery per patient, duration of infection, defect size, and follow-up time between Group A and Group B (P > 0.05). However, statistically significant differences were observed in operation time (187.13 ± 21.88 min vs. 255.76 ± 36.42 min, P = 0.002), intraoperative blood loss (39.26 ± 7.33 mL vs. 53.74 ± 10.69 mL, P < 0.001), external fixation time (2.02 ± 0.31 month vs. 2.57 ± 0.38 month, P = 0.045), external fixation index (0.27 ± 0.08 month/cm vs. 0.44 ± 0.09 month/cm, P = 0.042), and bone union time (8.37 ± 2.30 month vs. 9.07 ± 3.12, P = 0.032) between Group A and Group B. The excellent and good rate of bone and functional results were higher in Group A compared to Group B (76.9% vs. 75% and 84.6% vs. 58.3%). Statistically significant differences were observed in functional results (excellent/good/fair/poor, 5/6/2/0 vs. 2/5/4/1, P = 0.013) and complication per patient (0.38 vs. 1.16, P = 0.012) between Group A and Group B. CONCLUSIONS: Bone transport using a combined technique of external fixators over an intramedullary nail proved to be an effective method in treating tibial bone defects caused by infection. In comparison to circular external fixators, bone transport utilizing a unilateral external fixator over an intramedullary nail resulted in less external fixation time, fewer complications, and better functional outcomes.


Subject(s)
External Fixators , Manipulation, Osteopathic , Humans , Retrospective Studies , Fracture Fixation , Internal Fixators
2.
Article in English | MEDLINE | ID: mdl-38621188

ABSTRACT

We thoroughly investigated the anharmonic lattice dynamics and microscopic mechanisms of the thermal and electronic transport characteristics in orthorhombic o-CsCu5S3 at the atomic level. Taking into account the phonon energy shifts and the wave-like tunneling phonon channel, we predict an ultralow κL of 0.42 w/mK at 300 K with an extremely weak temperature dependence following ∼T-0.33. These findings agree well with experimental values along with the parallel to the Bridgman growth direction. The κL in o-CsCu5S3 is suppressed down to the amorphous limit, primarily due to the unconventional Cu-S bonding induced by the p-d hybridization antibonding state coupled with the stochastic oscillation of Cs atoms. The nonstandard temperature dependence of κL can be traced back to the critical or dominant role of wave-like tunneling of phonon contributions in thermal transport. Moreover, the p-d hybridization of Cu(3)-S bonding results in the formation of a valence band with "pudding-mold" and high-degeneracy valleys, ensuring highly efficient electron transport characteristics. By properly adjusting the carrier concentration, excellent thermoelectric performance is achieved with a maximum thermoelectric conversion efficiency of 18.4% observed at 800 K in p-type o-CsCu5S3. Our work not only elucidates the anomalous electronic and thermal transport behavior in the copper-based chalcogenide o-CsCu5S3 but also provides insights for manipulating its thermal and electronic properties for potential thermoelectric applications.

3.
Asian J Pharm Sci ; 19(2): 100908, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38623486

ABSTRACT

The disulfide bond plays a crucial role in the design of anti-tumor prodrugs due to its exceptional tumor-specific redox responsiveness. However, premature breaking of disulfide bonds is triggered by small amounts of reducing substances (e.g., ascorbic acid, glutathione, uric acid and tea polyphenols) in the systemic circulation. This may lead to toxicity, particularly in oral prodrugs that require more frequent and high-dose treatments. Fine-tuning the activation kinetics of these prodrugs is a promising prospect for more efficient on-target cancer therapies. In this study, disulfide, steric disulfide, and ester bonds were used to bridge cabazitaxel (CTX) to an intestinal lymph vessel-directed triglyceride (TG) module. Then, synthetic prodrugs were efficiently incorporated into self-nanoemulsifying drug delivery system (corn oil and Maisine CC were used as the oil phase and Cremophor EL as the surfactant). All three prodrugs had excellent gastric stability and intestinal permeability. The oral bioavailability of the disulfide bond-based prodrugs (CTX-(C)S-(C)S-TG and CTX-S-S-TG) was 11.5- and 19.1-fold higher than that of the CTX solution, respectively, demonstrating good oral delivery efficiency. However, the excessive reduction sensitivity of the disulfide bond resulted in lower plasma stability and safety of CTX-S-S-TG than that of CTX-(C)S-(C)S-TG. Moreover, introducing steric hindrance into disulfide bonds could also modulate drug release and cytotoxicity, significantly improving the anti-tumor activity even compared to that of intravenous CTX solution at half dosage while minimizing off-target adverse effects. Our findings provide insights into the design and fine-tuning of different disulfide bond-based linkers, which may help identify oral prodrugs with more potent therapeutic efficacy and safety for cancer therapy.

4.
J Agric Food Chem ; 72(15): 8618-8631, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38569082

ABSTRACT

Daidzein (DAN) is an isoflavone, and it is often found in its natural form in soybean and food supplements. DAN has poor bioavailability owing to its extremely low water solubility and first-pass metabolism. Herein, we hypothesized that a bioactivatable natural amino acid-bearing carbamate prodrug strategy could increase the water solubility and metabolic stability of DAN. To test our hypothesis, nine amino acid prodrugs of DAN were designed and synthesized. Compared with DAN, the optimal prodrug (daidzein-4'-O-CO-N-isoleucine, D-4'-I) demonstrated enhanced water solubility and improved phase II metabolic stability and activation to DAN in plasma. In addition, unlike the passive transport of DAN, D-4'-I maintained high permeability via organic anion-transporting polypeptide 2B1 (OATP2B1)-mediated transport. Importantly, D-4'-I increased the oral bioavailability by 15.5-fold, reduced the gender difference, and extended the linear absorption capacity in the pharmacokinetics of DAN in rats. Furthermore, D-4'-I exhibited dose-dependent protection against liver injury. Thus, the natural amino acid-bearing carbamate prodrug strategy shows potential in increasing water solubility and improving phase II metabolic stability to enhance the oral bioavailability of DAN.


Subject(s)
Isoflavones , Prodrugs , Animals , Rats , Administration, Oral , Amino Acids/chemistry , Biological Availability , Carbamates/chemistry , Prodrugs/chemistry , Solubility , Water
5.
Plants (Basel) ; 13(4)2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38498577

ABSTRACT

Salinity is one of the most common abiotic stress factors affecting different biochemical and physiological processes in plants, inhibiting plant growth, and greatly reducing productivity. During the last decade, silicon (Si) supplementation was intensively studied and now is proposed as one of the most convincing methods to improve plant tolerance to salt stress. In this review, we discuss recent papers investigating the role of Si in modulating molecular, biochemical, and physiological processes that are negatively affected by high salinity. Although multiple reports have demonstrated the beneficial effects of Si application in mitigating salt stress, the exact molecular mechanism underlying these effects is not yet well understood. In this review, we focus on the localisation of Si transporters and the mechanism of Si uptake, accumulation, and deposition to understand the role of Si in various relevant physiological processes. Further, we discuss the role of Si supplementation in antioxidant response, maintenance of photosynthesis efficiency, and production of osmoprotectants. Additionally, we highlight crosstalk of Si with other ions, lignin, and phytohormones. Finally, we suggest some directions for future work, which could improve our understanding of the role of Si in plants under salt stress.

6.
Environ Sci Pollut Res Int ; 31(13): 20499-20509, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38374508

ABSTRACT

In this study, nano-zero-valent iron/copper was synthesized by green tea extracts (GT-nZVI/Cu) and produced a stable suspension than nano-zero-valent iron synthesized by green tea extracts (GT-nZVI) injected into Cr(VI)-containing soil column. The equilibrium 1D-CDE model was successfully used to fit the penetration curves of Fe(tot), Fe(aq), and Fe(0) in order to determine the relevant parameters. The hydrodynamic dispersion coefficient of chromium-contaminated soil was 0.401 cm2·h-1, and the pore flow rate was 0.144 cm·h-1. The stable C/C0 of Fe(tot), Fe(aq), and Fe(0) in the effluent were retarded to 0.39, 0.79, and 0.11, respectively, compared to a ratio of 1 for the concentration of the tracer Cl- in the effluent to the concentration in the influent. Additionally, the 1D-CDE model describes the migration behavior of Cr(VI) with a high R2 (> 0.97). The obtained blocking coefficients declined gradually with increasing concentration of GT-nZVI/Cu suspension and decreasing concentration of Cr(VI). The content of reduced chromium in the soil decreased from 2.986 to 1.121 after remediation, while the content of more stable oxidizable chromium and residual chromium increased from 2.975 and 20.021 to 16.471 and 27.612. The phytotoxicity test showed that mung bean seeds still had a germination rate of 90% (control of 100%), root length of 29.63 mm (control of 35.25 mm), and stem length of 17.9 cm (control of 18.96 cm) after remediation with GT-nZVI/Cu. These indicated that GT-nZVI/Cu was effective in immobilizing Cr(VI) in the soil column and reduced the ecological threat. This study provides an analytical basis and theoretical model for the migration of chromium-contaminated soil in practical application.


Subject(s)
Environmental Restoration and Remediation , Soil Pollutants , Water Pollutants, Chemical , Copper , Soil Pollutants/analysis , Chromium/analysis , Soil , Iron , Tea , Plant Extracts , Water Pollutants, Chemical/analysis
7.
Chembiochem ; 25(7): e202300848, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38353515

ABSTRACT

We have recently discovered that ester-stabilized phosphorus ylides, resulting from deprotonation of a phosphonium salt such as [Ph3PCH2COOR], can transfer protons across artificial and biological membranes. To create more effective cationic protonophores, we synthesized similar phosphonium salts with one ((heptyloxycarbonylmethyl)(p-tolyl)bromide) or two ((butyloxycarbonylmethyl)(3,5-xylyl)osphonium bromide) methyl substituents in the phenyl groups. The methylation enormously augmented both protonophoric activity of the ylides on planar bilayer lipid membrane (BLM) and uncoupling of mammalian mitochondria, which correlated with strongly accelerated flip-flop of their cationic precursors across the BLM.


Subject(s)
Mitochondria, Liver , Phosphorus , Animals , Mitochondria, Liver/metabolism , Phosphorus/metabolism , Esters/metabolism , Bromides/metabolism , Methylation , Lipid Bilayers/metabolism , Mammals
8.
J Ethnobiol Ethnomed ; 20(1): 25, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38409040

ABSTRACT

BACKGROUND: Most fisher-gatherer communities we know of utilized a limited number of natural resources for their livelihood. The Turkic-speaking Loptuq (exonym Loplik, Loplyk) in the Lower Tarim River basin, Taklamakan desert, Eastern Turkestan (Xinjiang), were no exception. Their habitat, the Lop Nor marsh and lake area, was surrounded by desert and very poor in plant species; the Loptuq had to make the most of a handful of available biological resources for housing, furniture, clothing and fabric, fishnets and traps, tools and other equipment. The taxa used by the Loptuq were documented by foreign explorers at the end of the nineteenth and beginning of the twentieth centuries, prior to the forced resettlement of the group in the 1950s and subsequent destruction of their language, lifestyle and culture. METHODS AND SOURCES: Ethnobiology explores the relationship between humans and their environment, including the use of biological resources for different purposes. In several aspects, historical ethnobiology is more challenging; it studies this relationship in the past and therefore cannot verify results with informants. As the present study discusses an extinct culture on the basis of literary and material sources, we apply a method called source pluralism. This approach allows the inclusion and combination of a wide range of data and materials, even scraps of information from various sources, with the aim to understand phenomena which are sparsely mentioned in historical records. Travel reports by Swedish, British, German, American and Russian explorers together with linguistic data provide the most important sources for understanding Loptuq interaction with the environment and its biota. Especially the large number of toponyms and phytonyms recorded by the Swedish explorer Sven Hedin and materials from his expeditions, including voucher specimens kept in Stockholm in the herbarium of the Swedish Natural History Museum, and objects of material culture in the collections of the Ethnographical Museum, are crucial for our analysis about local knowledge among the Loptuq. Illustrations and photographs provide us with additional information. RESULTS: The question of how the Loptuq managed to survive at the fringe of a desert, a marsh and a lake which changed its location, intrigued all foreign visitors to the Lop Nor. The Loptuq's main livelihood was fishing, hunting and gathering, and their material culture provided by plants and other organic materials included their usage, consumption and trade. Only a handful of species formed the basis of the Loptuq material culture, but they had learned to use these specific plants for a variety of purposes. The most important of these were Lop hemp, Poacynum pictum (Schrenk) Baill., the riparian tree Euphrates poplar, Populus euphratica Olivier, and the aquatic common reed, Phragmites australis (Cav.) Trin. ex Steud. Several species of tamarisk were used for fuel and building fences. A few plants were also harvested for making foodstuffs such as snacks and potherbs. In addition, the Loptuq also used fur, bird skins, down, feathers, mammal bones and fish bones for their material needs. The habitat provided cultural ecological services such as motifs for their folklore, linguistic expressions and songs, and the Loptuq engaged in small-scale bartering of plant products and furs with itinerant traders, which ensured them with a supply of metal for making tools. CONCLUSION: This article discusses the now extinct Loptuq material culture as it existed more than a hundred years ago, and how the scarce biological resources of their desert and marsh habitat were utilized. Loptuq adaptation strategies to the environment and local knowledge, transmitted over generations, which contributed to their survival and subsistence, were closely connected with the use of biological resources. For this study, a comprehensive approach has been adopted for the complex relationships between human, biota and landscape. The Loptuq are today largely ignored or deleted from history for political reasons and are seldom, if at all, mentioned in modern sources about the Lop Nor area. Their experience and knowledge, however, could be useful today, in a period of rapid climate change, for others living in or at the fringe of expanding deserts.


Subject(s)
Ecosystem , Folklore , Animals , Humans , United States , Trees , Wetlands , Anthropology, Cultural , Mammals
9.
Sci Total Environ ; 919: 170752, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38340864

ABSTRACT

Elucidating whether dissolved Cu uptake is kinetically or thermodynamically controlled, and the effects of speciation on Cu transport by phytoplankton will allow better modeling of the fate and impact of dissolved Cu in the ocean. To address these questions, we performed Cu physiological and physicochemical experiments using the model diatom, Phaeodactylum tricornutum, grown in natural North Atlantic seawater (0.44 nM Cu). Using competitive ligand equilibration-cathodic stripping voltammetry (CLE-CSV), we measured two organic ligand types released by P. tricornutum to bind Cu (L1 and L2) at concentrations of ~0.35 nM L1 and 1.3 nM L2. We also established the presence of two putative Cu-binding sites at the cell surface of P. tricornutum (S1 and S2) with log K differing by ~5 orders of magnitude (i.e., 12.9 vs. 8.1) and cell surface densities by 9-fold. Only the high-affinity binding sites, S1, exhibit reductase activity. Using voltammetric kinetic measurements and a theoretical kinetic model, we calculated the forward and dissociation rate constants of L1 and S1. Complementary 67Cu uptake experiments identified a high- and a low-affinity Cu uptake system in P. tricornutum, with half-saturation constant (Km) of 154 nM and 2.63 µM dissolved Cu, respectively. In the P. tricornutum genome, we identified a putative high-affinity Cu transporter (PtCTR49224) and a putative ZIP-like, low-affinity Cu transporter (PtZIP49400). PtCTR49224 has high homology to Homo sapiens hCTR1, which depending on the accessibility to extracellular reducing agents, the hCTR1 itself is involved in the reduction of Cu2+ to Cu+ before internalization. We combined these physiological and physicochemical data to calculate the rate constants for the internalization of Cu, and established that while the high-affinity Cu uptake system (S1) is borderline between a kinetically or thermodynamically controlled system, the low-affinity Cu transporters, S2, is thermodynamically-controlled. We revised the inverse relationship between the concentrations of inorganic complexes of essential metals (i.e., Ni, Fe, Co, Zn, Cd, Mn and Cu) in the mixed layer and the formation rate constant of metal transporters in phytoplankton, highlighting the link between the chemical properties of phytoplankton metal transporters and the availability and speciation of trace metals in the surface ocean.


Subject(s)
Diatoms , Trace Elements , Humans , Diatoms/physiology , Ligands , Membrane Transport Proteins/metabolism , Membrane Transport Proteins/pharmacology , Metals/metabolism , Oceans and Seas , Phytoplankton/metabolism , Trace Elements/metabolism , Copper/chemistry
10.
Int J Biol Macromol ; 262(Pt 1): 130060, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38340938

ABSTRACT

Cordyceps sinensis exopolysaccharide­selenium nanoparticles (EPS-SeNPs) were successfully constructed, characterized, and its Se release kinetics and mechanism were also evaluated in our previous studies. However, the intestinal cellular uptake and transport capacities of EPS-SeNPs remain unknown. On the basis of our previous researches, this work was designed to evaluate the uptake and transport capacities of EPS-SeNPs (EPS/Se = 20/1, 3/1, 1/1, and 3/4) in intestinal epithelial (Caco-2) cells. Confocal laser scanning microscopy results indicated that the internalization of coumarin-6 labeled EPS-SeNPs was in a time-dependent process and eventually located in the cytoplasm, not in the nucleus. Endocytosis inhibitors were employed to evaluate the cellular uptake pathway of EPS-SeNPs, relevant results revealed that clathrin-, caveolae-, and energy-mediated pathways were participated in the internalization of EPS-SeNPs by Caco-2 cells. In addition, the transportation of EPS-SeNPs across Caco-2 cell monolayers was in a concentration-dependent manner. Different particle sizes of EPS-SeNPs presented different uptake and transport capacities in Caco-2 cells. Noteworthy, EPS/Se = 3/4 with the highest selenium content possessed the most superior cellular uptake and transport abilities in Caco-2 cells. The present work may contribute to illustrate the internalization and transport mechanism of EPS-SeNPs, thus facilitating its application in food and medical industries.


Subject(s)
Cordyceps , Nanoparticles , Selenium , Humans , Caco-2 Cells , Selenium/pharmacology , Particle Size , Nanoparticles/metabolism
11.
Am J Kidney Dis ; 83(6): 803-815, 2024 06.
Article in English | MEDLINE | ID: mdl-38372687

ABSTRACT

Magnesium is ubiquitous in nature. It sits at the origin of the food chain, occupying the center of chlorophyl in plants. In humans, magnesium is critical to diverse molecular and catalytic processes, including energy transfer and maintenance of the genome. Despite its abundance, hypomagnesemia is common and often goes undiagnosed. This is in spite of epidemiologic data linking low magnesium with chronic diseases including diabetes mellitus. Clinically significant hypermagnesemia is encountered less frequently, but the presentation may be dramatic. Advances in molecular biology and the elucidation of the genetic causes of magnesium disorders have enhanced our understanding of their pathophysiology. Treatment approaches are also changing. The repurposing of newer medications, such as sodium/glucose cotransporter 2 inhibitors, offers new therapeutic options. In this review we integrate knowledge in this rapidly evolving field to provide clinicians and trainees with a resource for approaching common clinical scenarios involving magnesium disorders.


Subject(s)
Magnesium Deficiency , Magnesium , Humans , Magnesium/blood , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use
12.
J Contam Hydrol ; 261: 104298, 2024 02.
Article in English | MEDLINE | ID: mdl-38242064

ABSTRACT

Groundwater contamination at legacy uranium processing sites is an ongoing global challenge. Plumes at many uranium-contaminated sites are more persistent than originally predicted by groundwater modeling. Previous investigations of uranium plume persistence identified residual and secondary sources that contribute to plume longevity, but there is a remaining need to revise forecasted cleanup times using information about these ongoing sources. The purpose of this study is to investigate the quantitative impact of residual vadose zone sources of uranium on groundwater remediation time frame. This objective was approached by applying numerical uranium transport simulations and uncertainty analysis to a former uranium mill site in the southwestern United States. Information from recent site investigations provided details about the distribution and release characteristics of uranium accumulations in the vadose zone. The residual uranium characteristics were incorporated as decaying source terms in the transport model. A stochastic approach using an iterative ensemble smoother was applied for history matching, and the transport model was used to assess the impact of multiple remedial alternatives on forecasted time frame. The forecasted time frame to achieve the groundwater remediation goal for uranium by monitored natural attenuation is on the order of thousands of years, and treatment of the dissolved plume does not reduce the projected time frame. The large proportion of residual uranium mass remaining in the vadose zone and the gradual leaching rate due to the site's semiarid climate create a long-lived source that can sustain a dissolved plume for thousands of years despite an estimated 99% mass removal achieved during mill tailings disposal. Residual uranium in vadose zone sediments beneath former tailings impoundments could present comparable uranium plume persistence and remediation challenges at other legacy uranium mill sites in semiarid climates. Other remaining uranium-impacted sites are similarly complex, and forecasted remedial time frames are needed to effectively achieve compliance, manage risk, assess the benefits of additional treatment, manage and project costs, and support beneficial site reuse.


Subject(s)
Groundwater , Uranium , Water Pollutants, Radioactive , Uranium/analysis , Water Pollutants, Radioactive/analysis
13.
J Pharm Pharmacol ; 76(5): 559-566, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38215001

ABSTRACT

Imperatorin (IMP) is the main bioactive furanocoumarin of Angelicae dahuricae radix, which is a well-known traditional Chinese medicine. The purpose of this study was to elucidate the role of IMP in promoting absorption and the possible mechanism on the compatible drugs of Angelicae dahuricae radix. The influence of IMP on drugs' intestinal absorption was conducted by the Caco-2 cell model. The mechanism was studied by investigating the transcellular transport mode of IMP and its influence on P-glycoprotein (P-gp)-mediated efflux, protein expression of P-gp and tight junction, and cell membrane potential. The result showed IMP promoted the uptake of osthole, daidzein, ferulic acid, and puerarin and improved the transport of ferulic acid and puerarin in Caco-2 cells. The absorption-promoting mechanism of IMP might involve the reduction of the cell membrane potential, decrease of P-gp-mediated drug efflux and inhibition of the P-gp expression level in the cellular pathway, and the loosening of the tight junction protein by the downregulation of the expression levels of occludin and claudin-1 in the paracellular pathway. This study provides new insights into the understanding of the improved bioavailability of Angelicae dahuricae radix with its compatible drugs.


Subject(s)
Angelica , Coumaric Acids , Coumarins , Furocoumarins , Intestinal Absorption , Isoflavones , Furocoumarins/pharmacology , Humans , Caco-2 Cells , Angelica/chemistry , Intestinal Absorption/drug effects , Isoflavones/pharmacology , Coumaric Acids/pharmacology , Coumaric Acids/pharmacokinetics , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/pharmacokinetics , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Tight Junctions/metabolism , Tight Junctions/drug effects , Biological Transport , Occludin/metabolism , Plant Roots
14.
ACS Nano ; 18(5): 4320-4328, 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38277645

ABSTRACT

Applying a drain bias to a strongly gate-coupled semiconductor influences the carrier density of the channel. However, practical applications of this drain-bias-induced effect in the advancement of switching electronics have remained elusive due to the limited capabilities of its current modulation known to date. Here, we show strategies to largely control the current by utilizing drain-bias-induced carrier type switching in an ambipolar molybdenum disulfide (MoS2) field-effect transistor with Pt bottom contacts. Our CMOS-compatible device architecture, incorporating a partially gate-coupled p-n junction, achieves multifunctionality. The ambipolar MoS2 device operates as an ambipolar transistor (on/off ratios exceeding 107 for both NMOS and PMOS), a rectifier (rectification ratio of ∼3 × 106), a reversible negative breakdown diode with an adjustable breakdown voltage (on/off ratio exceeding 109 with a maximum current as high as 10-4 A), and a photodetector. Finally, we demonstrate a complementary inverter (gain of ∼24 at Vdd = 1.5 V), which is highly facile to fabricate without the need for complex heterostructures and doping processes. Our study provides strategies to achieve high-performance ambipolar MoS2 devices and to effectively utilize drain bias for electrical switching.

15.
Environ Pollut ; 344: 123221, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38228263

ABSTRACT

Diffuse pollution, including that in the lower and middle reaches of the Yangtze River, is the primary source of pollution in several agricultural watersheds globally. As the largest river basin in China, the Yangtze River Basin has suffered from total phosphorus (TP) pollution in the past decade owing to diffuse pollution and aquatic ecology destruction, especially in the midstream tributaries and mid-lower reaches of the lakes. However, the transport dynamics of diffuse pollutants, such as phosphorus (P) from land to water bodies have not been well evaluated, which is of great significance for quantifying nutrient loss and its impact on water bodies. In this study, diffuse pollution estimation with remote sensing (DPeRS) model coupled with Soil and Water Assessment Tools (SWAT) was utilized to simulate the transport dynamics of P, investigate the spatial heterogeneity and P sources in the Poyang Lake Basin. Additionally, the P transport mechanism from land to water and the migration process in water bodies were considered to investigate the impact of each loss unit on the water body and evaluate the load generated by diverse pollution types. The estimated diffuse TP loss was 6016 t P·yr-1, and the load to inflow rivers and to Poyang Lake were 11,619 and 9812 t P·yr-1, respectively. Gan River Basin (51.09%) contributed most TP to Poyang Lake among five inflow rivers, while waterfront area demonstrated the highest TP load per unit area with 0.057 t km-2·yr-1. Our study also identified P sources in the sub-basins and emphasized agricultural diffuse sources, especially planting, as the most significant factor contributing to TP pollution. Additionally, to improve the aquatic environment and water ecological conditions, further nutrient management should be applied using a comprehensive approach that encompasses the entire process, from source transportation to the water body.


Subject(s)
Environmental Monitoring , Water Pollutants, Chemical , Lakes , Phosphorus/analysis , Water Pollutants, Chemical/analysis , China , Water , Nitrogen/analysis
16.
Int J Pharm ; 652: 123854, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38280499

ABSTRACT

Borneol is an aromatic traditional Chinese medicine that can improve the permeability of the blood-brain barrier (BBB), enter the brain, and promote the brain tissue distribution of many other drugs. In our previous study, borneol-metformin hydrochloride water/oil/water composite submicron emulsion (B-Met-W/O/W SE) was prepared using borneol and SE to promote BBB penetration, which significantly increased the brain distribution of Met. However, the dynamic images, transport pathway (uptake and efflux), promotion of BBB permeability, and mechanisms of B-Met-W/O/W SE before and after entering cells have not been clarified. In this study, rhodamine B and coumarin-6 were selected as water-soluble and oil-soluble fluorescent probes to prepare B-Met-W/O/W dual-fluorescent SE (B-Met-W/O/W DFSE) with concentric circle imaging. B-Met-W/O/W SE can be well taken up by brain microvascular endothelial cells (BMECs). The addition of three inhibitors (chlorpromazine hydrochloride, methyl-ß-cyclodextrin, and amiloride hydrochloride) indicated that its main pathway may be clathrin-mediated and fossa protein-mediated endocytosis. Meanwhile, B-Met-W/O/W SE was obviously shown to inhibit the efflux of BMECs. Next, BMECs were cultured in the Transwell chamber to establish a BBB model, and Western blot was employed to detect the protein expressions of Occludin, Zona Occludens 1 (ZO-1), and p-glycoprotein (P-gp) after B-Met-W/O/W SE treatment. The results showed that B-Met-W/O/W SE significantly down-regulated the expression of Occludin, ZO-1, and P-gp, which increased the permeability of BBB, promoted drug entry into the brain through BBB, and inhibited BBB efflux. Furthermore, 11 differentially expressed genes (DEGs) and 7 related signaling pathways in BMECs treated with B-W/O/W SE were detected by transcriptome sequencing and verified by quantitative real-time polymerase chain reaction (qRT-PCR). These results provide a scientific experimental basis for the dynamic monitoring, transmembrane transport mode, and permeation-promoting mechanism of B-Met-W/O/W SE as a new brain-targeting drug delivery system.


Subject(s)
Blood-Brain Barrier , Camphanes , Endothelial Cells , Blood-Brain Barrier/metabolism , Occludin/metabolism , Endothelial Cells/metabolism , Fluorescence
17.
Int J Biol Macromol ; 260(Pt 1): 129449, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38232885

ABSTRACT

Tea bags have been extensively used in the food industry and daily life as an efficient way to pack tea. However, the large pores of the commercial tea bags not only lead to the inner contents of tea bag susceptible to bacteria and moisture but also result in the faster water infusion which is undesired during tea brewing. In this study, the polylactic acid (PLA)-PLA/sodium alginate (SA)/bromelain (BL) bilayer fiber membrane imitating the asymmetric wetting structure of lotus leaf blades was fabricated to avoid the above disadvantages of commercial tea bag. The PLA/SA/BL skin-core nanofiber membrane which imitating the skin-core structure of lotus leaf stems was first prepared as the hydrophilic and support layer, then a hydrophobic PLA layer was deposited on top via electrospinning. The PLA-PLA/SA/BL bilayer fiber membrane had a breaking strength of 5.5 MPa and started to decompose at 260 °C. Using this bilayer membrane, tea bags were designed with a novel structure where the hydrophobic PLA layer was placed in the same direction. The novel structure endow the those tea bags a slow and directional water transfer property. Therefore, the PLA-PLA/SA/BL bilayer fiber membrane has great potential for applications as tea bags.


Subject(s)
Alginates , Bromelains , Water/chemistry , Polyesters/chemistry , Tea
18.
Water Res ; 252: 121195, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38290236

ABSTRACT

Successful in situ chemical oxidation (ISCO) applications require real-time monitoring to assess the oxidant delivery and treatment effectiveness, and to support rapid and cost-effective decision making. Existing monitoring methods often suffer from poor spatial coverage given a limited number of boreholes in most field conditions. The ionic nature of oxidants (e.g., permanganate) makes time-lapse electrical resistivity tomography (ERT) a potential monitoring tool for ISCO. However, time-lapse ERT is usually limited to qualitative analysis because it cannot distinguish between the electrical responses of the ionic oxidant and the ionic products from contaminant oxidation. This study proposed a real-time quantitative monitoring approach for ISCO by integrating time-lapse ERT and physics-based reactive transport models (RTM). Moving past common practice, where an electrical-conductivity anomaly in an ERT survey would be roughly linked to concentrations of anything ionic, we used PHT3D as our RTM to distinguish the contributions from the ionic oxidant and the ionic products and to quantify the spatio-temporal evolution of all chemical components. The proposed approach was evaluated through laboratory column experiments for trichloroethene (TCE) remediation. This ISCO experiment was monitored by both time-lapse ERT and downstream sampling. We found that changes in inverted bulk electrical conductivity, unsurprisingly, did not correlate well with the observed permanganate concentrations due to the ionic products. By integrating time-lapse ERT and RTM, the distribution of all chemical components was satisfactorily characterized and quantified. Measured concentration data from limited locations and the non-intrusive ERT data were found to be complementary for ISCO monitoring. The inverted bulk conductivity data were effective in capturing the spatial distribution of ionic species, while the concentration data provided information regarding dissolved TCE. Through incorporating multi-source data, the error of quantifying ISCO efficiency was kept at most 5 %, compared to errors that can reach up to 68 % when relying solely on concentration data.


Subject(s)
Environmental Restoration and Remediation , Groundwater , Manganese Compounds , Oxides , Trichloroethylene , Water Pollutants, Chemical , Trichloroethylene/chemistry , Groundwater/chemistry , Water Pollutants, Chemical/chemistry , Oxidation-Reduction , Oxidants , Tomography
19.
Nanotechnology ; 35(17)2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38176068

ABSTRACT

Realizing n- and p-type transition metal dichalcogenide (TMD)-based field-effect transistors for nanoscale complementary metal oxide semiconductor (CMOS) applications remains challenging owing to undesirable contact resistance. Quantumtransport calculations were performed by replacing single-sided Se atoms of TMD near the interface with As or Br atoms to further improve the contact resistance. Here, partial selenium replacement produced a novel interface with a segment of metamaterial MoSeX (Pt/MoSeX/MoSe2; X = As, Br). Such stable metamaterials exhibit semi-metallicity, and the contact resistance can be thus lowered. Our findings provide insights into the potential of MoSe2-based nano-CMOS logic devices.

20.
J Neural Eng ; 21(1)2024 01 31.
Article in English | MEDLINE | ID: mdl-38232381

ABSTRACT

Objective. The non-stationarity of electroencephalogram (EEG) signals and the variability among different subjects present significant challenges in current Brain-Computer Interfaces (BCI) research, which requires a time-consuming specific calibration procedure to address. Transfer Learning (TL) offers a potential solution by leveraging data or models from one or more source domains to facilitate learning in the target domain, so as to address these challenges.Approach. In this paper, a novel Multi-source domain Transfer Learning Fusion (MTLF) framework is proposed to address the calibration problem. Firstly, the method transforms the source domain data with the resting state segment data, in order to decrease the differences between the source domain and the target domain. Subsequently, feature extraction is performed using common spatial pattern. Finally, an improved TL classifier is employed to classify the target samples. Notably, this method does not require the label information of target domain samples, while concurrently reducing the calibration workload.Main results. The proposed MTLF is assessed on Datasets 2a and 2b from the BCI Competition IV. Compared with other algorithms, our method performed relatively the best and achieved mean classification accuracy of 73.69% and 70.83% on Datasets 2a and 2b respectively.Significance.Experimental results demonstrate that the MTLF framework effectively reduces the discrepancy between the source and target domains and acquires better classification performance on two motor imagery datasets.


Subject(s)
Brain-Computer Interfaces , Humans , Imagery, Psychotherapy , Electroencephalography/methods , Algorithms , Machine Learning , Imagination
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