Citrate Salts Research Articles

Optimization of Ferimzone and Tricyclazole Analysis in Rice Straw Using QuEChERS Method and Its Application in UAV-Sprayed Residue Study.

Rice straw is used as livestock feed and compost. Ferimzone and tricyclazole, common fungicides for rice blast control, can be found in high concentrations in rice straw after unmanned aerial vehicle (UAV) spraying, potentially affecting livestock and human health through pesticide residues. In this study, an optimized method for the analysis of the two fungicides in rice straw was developed using the improved QuEChERS method. After the optimization of water and solvent volume, extraction conditions including ethyl acetate (EtOAc), acetonitrile (MeCN), a mixed solvent, and MeCN containing 1% acetic acid were compared. Different salts, including unbuffered sodium chloride, citrate, and acetate buffer salts, were compared for partitioning. Among the preparation methods, the MeCN/EtOAc mixture with unbuffered salts showed the highest recovery rates (88.1-97.9%, RSD ≤ 5.1%). To address the severe matrix effect (%ME) of rice straw, which is characterized by low moisture content and cellulose-based complex matrices, samples were purified using 25 mg each of primary-secondary amine (PSA) and octadecylsilane (C18), without pesticide loss. The developed method was validated with a limit of quantification (LOQ) of 0.005 mg/kg for target pesticides, and recovery rates at levels of 0.01, 0.1, and 2 mg/kg met the permissible range (82.3-98.9%, RSD ≤ 8.3%). The %ME ranged from -17.6% to -0.3%, indicating a negligible effect. This optimized method was subsequently applied to residue studies following multi-rotor spraying. Fungicides from all fields and treatment groups during harvest season did not exceed the maximum residue limits (MRLs) for livestock feed. This confirms that UAV spraying can be safely managed without causing excessive residues.

Electrospun nanofibrous wound dressings with enhanced efficiency through carbon quantum dots and citrate incorporation

Nanofibers show promise for wound healing by facilitating active agent delivery, moisture retention, and tissue regeneration. However, selecting suitable dressings for diverse wound types and managing varying exudate levels remains challenging. This study synthesized carbon quantum dots (CQDs) from citrate salt and thiourea using a hydrothermal method. The CQDs displayed antibacterial activity against Staphylococcus aureus and Escherichia coli. A nanoscaffold comprising gelatin, chitosan, and polycaprolactone (GCP) was synthesized and enhanced with silver nanoparticle-coated CQDs (Ag-CQDs) to form GCP-Q, while citrate addition yielded GCP-QC. Multiple analytical techniques, including electron microscopy, FT-IR spectroscopy, dynamic light scattering, UV–Vis, photoluminescence, X-ray diffraction, porosity, degradability, contact angle, and histopathology assessments characterized the CQDs and nanofibers. Integration of CQDs and citrate into the GCP nanofibers increased porosity, hydrophilicity, and degradability—properties favorable for wound healing. Hematoxylin and eosin staining showed accelerated wound closure with GCP-Q and GCP-QC compared to GCP alone. Overall, GCP-Q and GCP-QC nanofibers exhibit significant potential for skin tissue engineering applications.

Novel avenue of carotenoids & omega-3 rich carrot waste extract in innovative table spread: optimization (based on texture and sensory) and characterization

Carrot waste is a rich source of pro-vitamin A, β-carotene, recognized for its immunomodulatory and health-promoting properties. The present study was aimed at formulating an innovative table spread (ITS) enriched with concentrated carotenoid extract derived from carrot pomace. Prior extraction of carotenoids in flaxseed oil was optimized resulting in extract (CE) rich in carotenoids (82.66 µg/g) and alpha-linolenic acid (ALA). The effects of three ingredients i.e. CE, tri-sodium citrate (TC), and common salt (CS) on ITS formulated using 33 factorial experiment (27 treatment combinations) were determined employing three-way ANOVA of Proc GLM method of SAS 9.3 for its textural and sensory acceptability. The optimized formulation contained 15% CE, 1.0% CS and 0.3% TC. ITS displayed medium (≈51% fat) internal phase emulsion (confirmed via fluorescence microscopy) stabilized (-56.867 mV ± 0.850 zeta potential) by whey protein concentrate and possessed high thermal stability (studied through thermogravimetric analysis). The control table spread (CTS) was prepared using all ingredients except CE replaced with flaxseed oil. ITS showed significantly (p < 0.05) higher carotenoid, antioxidant (ABTS, DPPH and FRAP), yellowness index and b* value than CTS; while non-significant (p > 0.05) difference existed for proximate composition and acidity. ITS turned out to be a naturally colored functional product and excellent source of carotenoids (24.276 μg/g ± 0.076) and ALA (13.816 g/ 100 g fat).

Physiologically Based Biopharmaceutics Modeling for Gefapixant IR Formulation Development and Defining the Bioequivalence Dissolution Safe Space.

Gefapixant is a weakly basic drug which has been formulated as an immediate release tablet for oral administration. A physiologically based biopharmaceutics model (PBBM) was developed based on gefapixant physicochemical properties and clinical pharmacokinetics to aid formulation selection, bioequivalence safe space assessment and dissolution specification settings. In vitro dissolution profiles of different free base and citrate salt formulations were used as an input to the model. The model was validated against the results of independent studies, which included a bioequivalence and a relative bioavailability study, as well as a human ADME study, all meeting acceptance criteria of prediction errors ≤ 20% for both Cmax and AUC. PBBM was also applied to evaluate gastric pH-mediated drug-drug-interaction potential with co-administration of a proton pump inhibitor (PPI), omeprazole. Model results showed good agreement with clinical data in which omeprazole lowered gefapixant exposure for the free base formulation but did not significantly alter gefapixant pharmacokinetics for the citrate based commercial drug product. An extended virtual dissolution bioequivalence safe space was established. Gefapixant drug product batches are anticipated to be bioequivalent with the clinical reference batch when their dissolution is > 80% in 60 minutes. PBBM established a wide dissolution bioequivalence space as part of assuring product quality.

Complete removal of organophosphate pesticides from wastewaters with sustainable ionic liquid-based aqueous two-phase strategy

Due to extensive food production, organophosphate pesticides (OPs) are widely utilized for crop protection, leading to their presence in the environment. The focus of this study was the design of an efficient aqueous biphasic system (ABS) strategy for OP removal, namely, malathion (MAL), azinphos-methyl (AZM), and chlorpyrifos (CHP) from water. Different ionic liquids (ILs) with symmetrical cations were selected as ABS phase-formers (tetrabutylphosphonium salicylate, tetrabutylammonium salicylate, 1,3-dibutylimidazolium dicyanamide, 1,3-dibutylimidazolium salicylate and 1,3-dibutylimidazolium bromide) with citrate salt as a salting-out agent. Initially, phase diagrams were determined, followed by partition studies revealing that the partition of MAL and CHP aligns with the IL- ABS formation trend, while the AZM partition is governed by specific interactions with ILs. For optimization studies, tetrabutylphosphonium-salicylate i.e. [TBP][Sal]-based ABS was chosen, due to obtained high extraction efficiencies of over 99.3 %. After establishing the effects of pH, temperature, tie-line length, and phase ratio on extraction performance, extraction of OPs from a real wastewater sample further confirmed the effectiveness of the designed method achieving complete removal of each pesticide. Furthermore, recovery of IL was achieved using an antisolvent method to precipitate CHP followed by IL-reuse in three consecutive cycles without efficiency decreased. Finally, it was demonstrated that [TBP][Sal] exhibits low cytotoxic potential, indicating that the presence of low amounts of this IL in aqueous media could be acceptable from ecotoxicological standpoint. This study showcased the exceptional potential of the proposed technology for the efficient and sustainable treatment of wastewater contaminated with OPs, affirming its capability to treat significant wastewater volumes.

Development of masked silica tanning system for sustainable leather production.

Amid mounting pressure on the long-term recyclability of chromium in tanned leather and the associated environmental hazards, the quest for an alternative, cleaner tanning system has gained tremendous momentum. In this context, our study explores the remarkable potential of silicates as a versatile platform for skin/hide tanning, circumventing the inherent risks and ecological threats posed by chromium exposure and leaching. We present an alternative approach of using a silica-based tanning system, employing a Taguchi model, to optimize a masked silica (MaSil) tanning product/process for achieving effective collagen stabilization. Our results demonstrate the significant advancements made in hydrothermal denaturation temperature, reaching an impressive 79 °C through precise Taguchi parameters-5% SiO2, masked with 0.3 mole of citrate salt, and a tanning process fixation pH of 4.5. Notably, the mechanical strength analysis reveals compliance with the stringent upper leather recommendation standards, validating the practicality and quality of MaSil crust leather. Moreover, our research highlights the unprecedented environmental benefits of the first reported application of Taguchi's approach to the MaSil tanning system. The developed tanning system remarkably reduces total dissolved solids (TDS), biological oxygen demand (BOD), chemical oxygen demand (COD), and overall water load by 68.4%, 25.4%, 59.5%, and 33.7%, respectively, heralding a promising era of water and environmental sustainability in the leather sector. This study holds the potential to transform leather production, wherein the envisioned future on the use of the Taguchi model and optimized MaSil tanning system could find a place in shaping a cleaner, greener, and more sustainable leather industry.

Separation and purification of phycobiliproteins from Thermosynechococcus PCC 6715 by foam fractionation and aqueous twophase extraction

The use of foam fractionation followed by aqueous two-phase extraction has emerged as a potential alternative to traditional liquid chromatography, hitherto irreplaceable in the purification of phycobiliproteins. The crude extracts of C-phycocyanin and allophycocyanin were obtained after Thermosynechococcus PCC 6715 biomass disintegration. The FF process with air flow of 2.4 L·h -1 resulted in purification factors up to 1.47 and partitioning coefficients of about 39, and did not require the addition of surfactants. A temperature of 35˚C allowed for the highest partitioning coefficient of 67.6 and yield of 76%; however, the purity of C-PC in condensate at this temperature was lower than at 25˚C. ATPE was tested in 20 different systems consisting of polyethylene glycol and phosphate or citrate salts, of which PEG1500-citrate gave the highest purification factor value of 2.31. Conversely, a partitioning coefficient of 2416 and 1094 were obtained for the PEG1500-phosphate and PEG3000-phosphate systems, respectively. Interestingly, the use of FF condensate in subsequent ATPE step resulted, for the first time, in the separation of the polymer phase into two fractions, one contained C-phycocyanin and the other allophycocyanin. It can be concluded that the use of a two-step system of FF and ATPE is a viable way to separate phycobiliproteins.

Iron Citrate (Synthesit) Supplementation During Pancreas Cancer Showed Surprising Results – Case Study

Abstract Iron is a crucial mineral for our organism and its deficiency can cause serious health problems such as anaemia, fatigue, and impaired physical fitness. It has been shown that anaemia or iron deficiency is very common in patients with cancer. These patients benefit from iron supplementation either in intravenous or oral form. Our patient is a 67-year-old Russian woman with pancreatic cancer diagnosed in 2019. She fought off lymphocytic leukaemia in 2015. She refused treatment for her pancreatic cancer. The specific type of pancreatic cancer was not specified as the patient chose not to undergo targeted testing. Between March 2020 and February 2023, she took the dietary supplement Synthesit for three cycles (1 cycle lasted about a month). After taking the dietary supplement, a total percentage of neutrophils became in the reference range. Subjectively, the patient started to feel better after taking Synthesit and her quality of life and well-being has improved as well. It might be supposed that the dietary supplement could have some effect on her well-being and various blood parameters such as white cells count. Even though the dietary supplement is not supposed to be used for treatment of diseases, it can change some blood parameters and improve the immune system. This short case study presents the patient with pancreatic cancer who started to take the dietary supplement Synthesit which contains iron in the form of citrate salt in a dosage of 800 μg per capsule, 1 capsule per day. The dietary supplement was administered over three treatment cycles (1 cycle took about a month) from March 2020 to February 2023. It describes a difference in blood test results before taking Synthesit and after the administration of Synthesit.

Studies on the interference of citrate salts on the ion–solvent interactions of ionic liquid with water at different temperatures through volumetric, viscometric, and acoustic methods

The density, viscosity, and ultrasonic velocity of solutions of imidazolium-based ionic liquid, 1-ethyl-3-methyl imidazolium ethyl sulphate ([EMIm][EtSO4]) with aqueous solutions of sodium and potassium salts of citrate have been measured at five different temperatures i.e., T = (298.15–318.15) K and 0.1 MPa pressure. The experimentally found density (ρ) data have been utilized to compute the different volumetric properties such as apparent molar volume (Vϕ), partial molar volume (Vϕ0), partial molar expansivity (Eϕ0), Hepler’s constant (∂Eϕ0/∂T)p and volume transfer (ΔtrVϕ0). Similarly, the Jones-Dole equation, viscosity B-coefficient, transfer properties of B-Coefficient, (ΔtrB) and thermodynamics of viscous flow were calculated from viscosity consequences. The compression properties such as apparent molar isentropic compressibility (Kϕ,S), partial molar compressibility (Kϕ,S0) and transfer partial molar compressibility (ΔtrKϕ,S0) of IL have been deduced from the ultrasonic velocity. All the derived properties have been used to investigate the impact of citrate salts on the ion–solvent interactions of [EMIm][EtSO4] with water. The positive value of each of Hepler’s constants, and ΔtrKϕ,S0 and the negative sign of (dB/dT) indicates the existence of strong ion–solvent interactions and the cosmotrope nature of [EMIm][EtSO4] in the studied systems at the studied temperature ranges. The ion–solvent interactions of the present IL are found to be more in the solutions of potassium citrate (K3Cit) than sodium citrate (Na3Cit).

Synthesis, Characterization, and Stability Assessment for the Benzoate, Hydrochloride, Malonate, and Nicotinate Salts of Bedaquiline.

Bedaquiline has been approved as a combination therapy to treat multi-drug-resistant tuberculosis in adults ≥ 18 years old. The citrate, fumarate, phosphate, and tartrate salts have obtained patents, but the structures for these moieties have not been extensively described in the literature; only the powder X-ray patterns have been published. To expand the knowledge of the bedaquiline structure, this study provides detailed information for the synthesis, elucidation, characterization, and stability of four additional new potential molecular entities, namely, benzoate, hydrochloride (HCl), nicotinate, and malonate salts. The salts were formed using a 1:1 ratio of the counter ions (acids) to a 30 mg equivalent of the bedaquiline free base. The principles of the International Conference on Harmonization Q6 were used to characterize the new salts and their stability-indicating parameters were evaluated at 0, 3, and 6 months under accelerated conditions of 40 °C and 75% relative humidity. The benzoate salt exhibited the lowest tendency to lose its chemical potency. Aside from the HCl salt, the others retained their chemical structure, displaying long-term stability. All salts were non-hygroscopic and the hydrated benzoate and nicotinate salts were stable to dehydration. Regarding their chemical potencies, thermal analysis, chemical stability, and water sorption potential, the salts were ranked as follows: benzoate > malonate > nicotinate > HCl.

The mechanisms of alkali therapy in targeting renal diseases.

Chronic kidney disease (CKD) is characterized by progressive reduction in kidney function and treatments aiming at stabilizing or slowing its progression may avoid or delay the necessity of kidney replacement therapy and the increased mortality associated with reduced kidney function. Metabolic acidosis, and less severe stages of the acid stress continuum, are common consequences of CKD and some interventional studies support that its correction slows the progression to end-stage kidney disease. This correction can be achieved with mineral alkali in the form of bicarbonate or citrate salts, ingestion of diets with fewer acid-producing food components or more base-producing food components, or a pharmacological approach. In this mini-review article, we summarize the potential mechanisms involved in the beneficial effects of alkali therapy. We also discuss the perspectives in the field and challenges that must be overcome to advance our understanding of such mechanisms.

Troublesome Teeth, Search for Stones – Enamel-Renal Syndrome

Background: Enamel-renal syndrome (ERS), is a rare autosomal recessive disorder involving family with sequence similarity 20 member A (FAM20A) gene. This unique syndrome is characterized by severe enamel hypoplasia, intrapulpal calcification, nephrocalcinosis, or nephrolithiasis. This case report highlights the early presentation and incidental detection of chronic kidney disease (CKD) in a young child with enamel defects. Clinical Description: A 10-year-old girl, with no significant past or family history, presented with delayed tooth eruption and abnormal shaped teeth. She was detected to have generalized gingival hyperplasia and multiple unerupted teeth. Suspecting amelogenesis imperfecta, she was screened for coexisting systemic conditions. On evaluation, abdominal ultrasound demonstrated bilateral nonobstructive nephrolithiasis. Further renal workup done showed an abnormal creatinine (stage 2 CKD) and mild metabolic acidosis. Reduced urinary citrate excretion with no evidence of hypercalciuria was noted on extensive urine assessment. Genetic testing revealed a novel pathogenic variant in FAM20A, confirming the diagnosis of ERS. Management: The child was initiated on citrate supplements, salt restriction, and adequate hydration. She was advised of dental interventions, including pulp therapy and full-coverage restoration of decayed teeth. The family was counseled about the need for close monitoring of growth, renal function, and progression of nephrolithiasis. Conclusion: Prompt screening for renal associations in oro-dental and systemic disease must be undertaken to ensure early detection of kidney disease and timely institution of appropriate treatment. In children diagnosed to have kidney involvement, the importance of regular follow-up with clinical, biochemical, and imaging modalities, even during adulthood, must be emphasized.

Structural Analysis of the Novel Chlorhexidine Perchlorate and Hydrogen Citrate Salts

Structural Analysis of the Novel Chlorhexidine Perchlorate and Hydrogen Citrate Salts

Растворение мочекислых камней мочеточника

Uric acid stones (UA), consisting of uric acid/uric acid dihydrate, occur in 6.1-15.1% of all cases of urolithiasis in industrialized countries. At the same time, the frequency of these stones is directly dependent on age. Thus, the incidence of UA reaches 40% in men over 80 years of age and 27.3% in women over 90 years of age. UA are the only stones that are amenable to dissolution therapy with the use of citrate salts that alkalinize urine pH. A number of authors and European Association of Urology guidelines consider stone dissolution as a first-line therapy in the treatment of patients with UA, both as monotherapy and in combination with surgical procedures.The results of conservative treatment of 86 patients aged 28 to 78 years with radiolucent ureteral stones ranging in size from 3 to 25 mm and a density of 133 to 728 HU, who underwent 89 courses of stone dissolution therapy from 2011 to 2018, are presented in the article. They had no obstruction or were prestented. There were 52 men (n=55 courses) and 34 women (n=34 courses).In 78 out of 89 clinical cases (87.6%), stone-free status was obtained within 14 to 181 days. Most often the duration of therapy was 30 days. In 11 (12.4%) cases the treatment was considered ineffective. However, only in 4 (4.5%) patients the stone size did not change, while in 7 (7.9%) cases it decreased. The results of the study suggest the high efficiency of citrate therapy in patients with ureteral stones in case of unobstructed urine outflow (including those with stents), which is comparable to surgical treatment.

Self-nanoemulsifying formulation for oral delivery of sildenafil: effect on physicochemical attributes and in vivo pharmacokinetics.

Sildenafil (SLD) is employed for the management of erectile dysfunction and pulmonary arterial hypertension. It exhibits meagre water solubility and is available in the form of citrate salt hydrate to improve the solubility. However, it still exhibits moderate solubility, high first-pass metabolism, resulting in very less oral bioavailability. The present study demonstrates the preparation of self-nanoemulsifying drug delivery system for augmenting the oral bioavailability of SLD. Oleic acid and Capmul MCM C8 blend (oil phase), Cremophor® RH40 (surfactant), and Labrafil® M1944 CS (cosurfactant) were selected as main constituents for making liquid preconcentrate based on the solubility and emulsification study. The preconcentrate upon dilution and emulsification showed droplet size 52.03 ± 13.03nm, PDI 0.143 ± 0.028, and % transmittance was 99.77 ± 1.86% with SLD load of 40mg/g of formulation. The prepared formulation was further assessed for stability, in vitro release, Caco-2 cell uptake, and in vivo pharmacokinetic performance. SLD-SNEDDS formulation was found to be robust in terms of stability against several folds dilution in the gastrointestinal tract (GIT), freeze-thaw cycles, and had a storage stability of 3months at 4°C and 25°C. SLD-SNEDDS showed ~4.7-fold and ~5-fold increase in time- and concentration-dependent cellular uptake as against SLD cultured with Caco-2 cells. In vivo pharmacokinetic study revealed ~5.8- and ~2.5-fold increase in AUC0-∞ values in case of SLD-SNEDDS as against SLD suspension and SLD citrate solution, respectively.

Ionic strength and buffering capacity of emulsifying salts determine denaturation and gelation temperatures of whey proteins

Ionic conditions affect the denaturation and gelling of whey proteins, affecting the physical properties of foods in which proteins are used as ingredients. We comprehensively investigated the effect of the presence of commonly used emulsifying salts on the denaturation and gelling properties of concentrated solutions of β-lactoglobulin (β-LG) and whey protein isolate (WPI). The denaturation temperature in water was 73.5°C [coefficient of variation (CV) 0.49%], 71.8°C (CV 0.38%), and 69.9°C (CV 0.41%) for β-LG (14% wt/wt), β-LG (30% wt/wt), and WPI (30% wt/wt), respectively. Increasing the concentration of salts, except for sodium hexametaphosphate, resulted in a linear increase in the denaturation temperature of WPI (kosmotropic behavior) and an acceleration in its gelling rate. Sodium chloride and tartrate salts exhibited the strongest effect in protecting WPI against thermal denaturation. Despite the constant initial pH of all solutions, salts having buffering capacity (e.g., phosphate and citrate salts) prevented a decrease in pH as the temperature increased above 70°C, resulting in a decline in denaturation temperature at low salt concentrations (≤0.2 mol/g). When pH was kept constant at denaturation temperature, all salts except sodium hexametaphosphate, which exhibited chaotropic behavior, exhibited similar effects on denaturation temperature. At low salt concentration, gelation was the controlling step, occurring up to 10°C above denaturation temperature. At high salt concentration (>3% wt/wt), thermal denaturation was the controlling step, with gelation occurring immediately after. These results indicate that the ionic and buffering properties of salts added to milk will determine the native versus denatured state and gelation of whey proteins in systems subjected to high temperature, short time processing (72°C for 15 s).

Novel aqueous two-phase systems containing polymer-based deep eutectic solvent and citrate salts for high-performance extraction of dyes

• ATPs containing DESs and sodium or potassium citrate were studied. • The effects of salt and temperature on phase separation were discussed. • The ATPSs were used for extraction of methyl orange, methylene blue and congo red. • Higher extraction efficiency was obtained with congo red than the other dyes. The release of synthetic dyes into the aquatic environment, cause to both economic and environmental concerns owing to its pernicious effect. Until now, various dyes removal methodologies have been developed much attention in separation fields. Aqueous two-phase systems (ATPSs) are considered as utmost important and significant method for the separation field because the main component of the two phases is water. In the current study, the ATPSs have been constructed by either polypropylene glycol 400 (PPG 400 ) or deep eutectic solvent (DES) based on PPG 400 and tetrabutylammonium bromide (TBAB) with two citrate salts (sodium or potassium). These systems have been applied to explore their capability for the partitioning and separation of the dyes namely methyl orange (MO), methylene blue (MB), and congo red (CR) from aqueous media. The binodal data were experimentally measured by the clouding point method at temperatures T = (298.15, 303.15, 308.15, and 313.15) K under 85 kPa. The obtained partition coefficients ( K ) and extraction efficiencies ( EE %) demonstrate that the mentioned dyes preferentially were distributed into the PPG 400 or DES-rich phase. The measured binodal data were fitted by two semi-empirical Merchuk and Zafarani-Moattar et al. equations. The salt effect indicates that the ability of Na + is more than K + , which follows the Hofmeister series and can be related to the ions Gibbs free energy of hydration ( Δ G hyd ). Finally, it can be observed that the potential of the studied dyes to transfer into the top phase obeyed the following trend: CR > MO > MB in all the studied systems and the ATPSs methodology provided a high degree of dye removal (98%) from the water.

Simple Halogen-Free, Biobased Organic Salts Convert Glycidol to Glycerol Carbonate under Atmospheric CO2 Pressure.

Glycerol carbonate (GC) has emerged as an attractive synthetic target due to various promising technological applications. Among several viable strategies to produce GC from CO2 and glycerol and its derivatives, the cycloaddition of CO2 to glycidol represents an atom-economic an efficient strategy that can proceed via a halide-free manifold through a proton-shuttling mechanism. Here, it was shown that the synthesis of GC can be promoted by bio-based and readily available organic salts leading to quantitative GC formation under atmospheric CO2 pressure and moderate temperatures. Comparative and mechanistic experiments using sodium citrate as the most efficient catalyst highlighted the role of both hydrogen bond donor and weakly basic sites in the organic salt towards GC formation. The citrate salt was also used as a catalyst for the conversion of other epoxy alcohols. Importantly, the discovery that homogeneous organic salts catalyze the target reaction inspired us to use metal alginates as heterogeneous and recoverable bio-based catalysts for the same process.

Nicotinic acetylcholine signaling is required for motor learning but not for rehabilitation from spinal cord injury.

Therapeutic intervention for spinal cord injury is limited, with many approaches relying on strengthening the remaining substrate and driving recovery through rehabilitative training. As compared with learning novel compensatory strategies, rehabilitation focuses on restoring movements lost to injury. Whether rehabilitation of previously learned movements after spinal cord injury requires the molecular mechanisms of motor learning, or if it engages previously trained motor circuits without requiring novel learning remains an open question. In this study, mice were randomly assigned to receive intraperitoneal injection with the pan-nicotinic, non-competitive antagonist mecamylamine and the nicotinic α7 subunit selective antagonist methyllycaconitine citrate salt or vehicle (normal saline) prior to motor learning assays, then randomly reassigned after motor learning for rehabilitation study post-injury. Cervical spinal cord dorsal column lesion was used as a model of incomplete injury. Results of this study showed that nicotinic acetylcholine signaling was required for motor learning of the single pellet-reaching task but it was dispensable for the rehabilitation of the same task after injury. Our findings indicate that critical differences exist between the molecular mechanisms supporting compensatory motor learning strategies and the restoration of behavior lost to spinal cord injury.

Terahertz Metamaterial Sensor for Sensitive Detection of Citrate Salt Solutions.

Citrate salts (CSs), as one type of organic salts, have been widely used in the food and pharmaceutical industries. Accurate and quantitative detection of CSs in food and medicine is very important for health and safety. In this study, an asymmetric double-opening ring metamaterial sensor is designed, fabricated, and used to detect citrate salts combined with THz spectroscopy. Factors that influence the sensitivity of the metamaterial sensor including the opening positions and the arrangement of the metal opening ring unit, the refraction index and the thickness of the analyte deposited on the metamaterial sensor were analyzed and discussed from electromagnetic simulations and THz spectroscopy measurements. Based on the high sensitivity of the metamaterial sensor to the refractive index of the analyte, six different citrate salt solutions with low concentrations were well identified. Therefore, THz spectroscopy combined with a metamaterials sensor can provide a new, rapid, and accurate detection of citrate salts.