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Microplastics are increasingly recognised as posing a significant environmental threat across systems. Their pervasive presence in freshwater poses a serious concern, given the heavy reliance of both humans and biodiversity on healthy, functioning freshwater ecosystems. Acknowledgment of the potential risks led the transboundary Orange-Senqu River Commission (ORASECOM) to include sampling for microlitter (primarily microplastics) in riverine sediment, surface water, and fishes, across Southern Africa as part of the third Joint Basin Survey (JBS3) in 2021. The aim was to establish a first, basin-wide estimate of microlitter contamination across compartments, setting a baseline for further monitoring. The survey showed that the abundance of microlitter in riverine sediment (0 - 4000 particles.kg -1 dry weight (dw)) and riverine water (1.00 ± 0.71 - 69.75 ± 68.55 SD items.L -1 ) varied considerably between sample sites, with no correlation between the two. The abundance of microlitter in fishes was low (average of 0.7 ± 0.4 items.individual -1 ). Course resolution analyses suggested that microlitter concentrations in riverine sediment and riverine water at each site did not correlate with land use directly upstream, though variation in microlitter abundance did isolate some hotspots of contamination. Discharge data collected from nine gauging stations near sampling sites confirmed that low flows prevailed in the system during the study, with high flows occurring approximately 5 months prior during the summer months. There is some variation in river flow across the catchment which is a likely driver of microlitter transport. This was evident in the polymer composition for sediment and water samples. Based on the average discharge at each gauging station and microlitter concentrations measured in riverine water, the estimated microlitter load ranged from ∼889 particles.s -1 to ∼17.9 million particles.s -1 , with a substantial amount ending likely up in the mudbelt adjacent to the Orange River mouth. This assessment provides a first insight into the characterisation and distribution of microlitter in multiple compartments across the Orange-Senqu River basin. Overall, the findings highlight the need for continued monitoring across compartments at catchment scales to improve our understanding of microplastic pathways into and within riverine systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Nickel monocarbonyl species with Ni(I) and Ni(0) have been synthesized and fully characterized by employing an acri PNP-Ph pincer ligand having a -C(Ph) 2 - bridge moiety to tether two aromatic rings. To see the effect of the bridge moiety, these complexes were structurally compared with the previously studied nickel complexes supported by PNP and acri PNP-Me ligands and methylation of the nickel carbonyl species was particularly investigated. Since a Ni(I)-CO species is known to be one of the key intermediates during the C-C coupling reaction to give an acetyl species, according to the paramagnetic mechanism of acetyl coenzyme A synthase (ACS), their reactivity toward MeI has been examined. Methylation of a nickel(I)-CO species reveals enhanced C-C coupling when both acri PNP-Me and acri PNP-Ph ligands were used. According to spin density analysis calculated by density functional theory, all Ni(I)-CO species reveal similar spin density at nickel and the carbon atom of CO. X-ray crystallographic data suggest that the corresponding selectivity may be related to the steric influence. For both ( acri PNP-Ph)Ni-CO (2) and ( acri PNP-Me)Ni-CO (2'), the nickel(I) site is sterically well protected, leading to selective interaction with a methyl radical to give a nickel acyl product. Steric influence was marginally observed when an anionic {( acri PNP-R)Ni-CO} - (R = Me or Ph) species reacted with MeI. The corresponding C-C coupled product was also observed from the methylation of nickel(0)-CO species.

Atlantic tarpon Megalops atlanticus are highly migratory sportfish that support recreational fisheries throughout their range. In US waters, juveniles can be found in coastal and estuarine habitats along the Gulf of Mexico and Atlantic seaboard, with temperature limiting their northern latitudinal distribution. Juveniles may overwinter in these areas during the first several years of life. Low temperatures are known to cause mortality in adults, but the challenges of temperature are less understood for juveniles. Furthermore, salinity, which can change dramatically in these habitats, may have a synergistic effect with temperature. To examine the physiological effects of temperature and salinity on juvenile tarpon, wild fish were acclimated to a range of conditions that potentially occur in the northern range of their estuarine habitats. The haematology of juvenile tarpon was examined in two salinity (≤2 and ≥30 ppt) and temperature (15 and 25°C) treatments, followed by a low-temperature tolerance test. After 2 weeks in treatment conditions, blood samples were analysed for haematocrit, pH, red blood cell concentration, haemoglobin content and plasma osmolality. Increased plasma osmolality was observed in fish at low temperature (15°C compared to 25°C) and at high salinity (≥30 ppt compared to ≤2 ppt). Blood pH was increased at 15°C compared to 25°C, with the highest pH at 15°C and low salinity. Haemoglobin, haematocrit and red blood cell concentration were higher at 25°C than 15°C, with haemoglobin lowest at 15°C and low salinity. For the low-temperature tolerance test, all fish were acclimated to 15°C for 2 weeks, then transferred to separate tanks where temperature was gradually decreased at 0.9 ± 0.1°C/h until fish lost equilibrium. Fish at low salinity lost equilibrium more rapidly (1 ppt, 12.65 ± 0.46°C) than fish at high salinity (30 ppt, 11.26 ± 0.14°C). The results indicate juvenile tarpon are susceptible to low temperature, which is exacerbated by low salinity, findings useful in the assessment of juvenile tarpon overwintering habitat., (© 2023 Fisheries Society of the British Isles.)

Age and growth of early-life-stage Atlantic tarpon Megalops atlanticus collected from Mississippi coastal waters in the northcentral Gulf of Mexico (GOM) are described using otolith microstructure analysis. Tarpon leptocephali (n = 95, 16.0-27.8 mm standard length, L S ) collected from June throughOctober 2013-2018, ranged in age from 22 to 43 days (mean = 30.9 ± 0.5 days). Leptocephalus somatic growth rates ranged 0.46-1.24 mm day -1 (mean = 0.76 ± 0.02 mm day -1 ), and leptocephalus otolith growth rates ranged 1.78-3.97 μm day -1 (mean = 2.58 ± 0.04 μm day -1 ). Growth rates were inversely correlated to leptocephalus age, indicating the shrinkage phase associated with leptocephalus metamorphosis. Juvenile tarpon (n = 358, 50-359 mm fork length, L F ) were collected from August through December 2007-2018. Juveniles exhibited a positive allometric relationship (adjusted R 2  = 0.99, P < 0.001) between length and mass. The age of 100 juveniles (71-277 mm L F ) ranged from 76 to 174 days. Juvenile growth rate was estimated as 1.56 ± 0.11 mm day -1 . Significant (P < 0.001) linear relationships were found between juvenile age and otolith metrics, including otolith mass (R 2  = 0.81) and radius (R 2  = 0.68). Evaluation of the backcalculated hatch dates suggests that specimens in the collection hatched from late May through mid-September with slight peaks during July and August. A Rao's Spacing Test of Uniformity indicates the presence of significant lunar periodicity in leptocephalus hatch dates (n = 95, U = 250.1, P < 0.05), with 50% of the leptocephali hatched within 5 days (before or after) of the full moon. This study fills critical gaps in the scientific knowledge of tarpon and provides estimates of early-life-history metrics for an iconic game fish at the northernmost extent of its GOM range., (© 2021 Fisheries Society of the British Isles.)

A dinickel(0)-N 2 complex, stabilized with a rigid acridane-based PNP pincer ligand, was studied for its ability to activate C(sp 2 )-H and C(sp 2 )-O bonds. Stabilized by a Ni-μ-N 2 -Na + interaction, it activates C-H bonds of unfunctionalized arenes, affording nickel-aryl and nickel-hydride products. Concomitantly, two sodium cations get reduced to Na(0), which was identified and quantified by several methods. Our experimental results, including product analysis and kinetic measurements, strongly suggest that this C(sp 2 )-H activation does not follow the typical oxidative addition mechanism occurring at a low-valent single metal centre. Instead, via a bimolecular pathway, two powerfully reducing nickel ions cooperatively activate an arene C-H bond and concomitantly reduce two Lewis acidic alkali metals under ambient conditions. As a novel synthetic protocol, nickel(ii)-aryl species were directly synthesized from nickel(ii) precursors in benzene or toluene with excess Na under ambient conditions. Furthermore, when the dinickel(0)-N 2 complex is accessed via reduction of the nickel(ii)-phenyl species, the resulting phenyl anion deprotonates a C-H bond of glyme or 15-crown-5 leading to C-O bond cleavage, which produces vinyl ether. The dinickel(0)-N 2 species then cleaves the C(sp 2 )-O bond of vinyl ether to produce a nickel(ii)-vinyl complex. These results may provide a new strategy for the activation of C-H and C-O bonds mediated by a low valent nickel ion supported by a structurally rigidified ligand scaffold., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

En coup de sabre (ECDS) is a rare form of localized scleroderma that typically manifests in children and women. It presents as a fibrous pansclerotic plaque extending in a bandlike distribution on the frontoparietal scalp with surrounding scarring alopecia. Many patients have comorbid central nervous system involvement in addition to the cutaneous findings. En coup de sabre is a rare entity that should be delineated from Parry-Romberg syndrome, as both entities share some common features and may coexist. Corticosteroids remain the treatment of choice, but other modalities such as methotrexate, excimer laser, and grafting have been used with varying success. We report a case of an elderly woman who presented with an asymptomatic alopecic plaque consistent with ECDS.

Background: Microneedling is a relatively new treatment option in dermatology and has been touted for a broad range of applications including skin rejuvenation, acne scarring, rhytides, surgical scars, dyschromia, melasma, enlarged pores, and transdermal drug delivery. The significant increase in minimally invasive procedures that has been reported over the past several years suggest that microneedling may occupy a specific niche for patients who desire measurable clinical results from treatments with little to no recovery., Objective: To review the published medical literature relating to microneedling in dermatology and provide a practical guide for its use in clinical practice., Materials and Methods: A thorough literature search of microneedling in dermatology using PubMed was conducted, and all references pertaining to skin scarring and rejuvenation were reviewed. Based on the information presented in these publications and the authors' clinical experience, a microneedling technique is outlined for clinical practice. Pretreatment recommendations, intraoperative technique and treatment end points, and postoperative considerations are outlined., Results: Microneedling produces substantial clinical improvement of scars, striae, and rhytides with expedient recovery and limited side effects. Controlled dermal wounding and stimulation of the wound healing cascade enhances collagen production and is likely responsible for the clinical results obtained., Conclusion: Microneedling is a safe, minimally invasive, and effective esthetic treatment for several different dermatologic conditions including acne and other scars, rhytides, and striae. Given its expedient post-treatment recovery, limited side effect profile, and significant clinical results, microneedling is a valuable alternative to more invasive procedures such as laser skin resurfacing and deep chemical peeling.

A rare triad composed of lobular panniculitis in the setting of pancreatitis and polyarthritis is termed panniculitis, pancreatitis, and polyarthritis (PPP) syndrome. Pancreatic panniculitis is a rare form of subcutaneous fat necrosis associated with underlying pancreatic disease. We describe a case of PPP syndrome and review the relevant literature associated with this rare clinical syndrome. Despite numerous adjuvant therapies, definitive treatment of PPP syndrome requires correction of the underlying pancreatic disease.

Mesalamine (5-aminosalicylic acid, 5-ASA) is known to be the first-line medication for treatment of patients with ulcerative colitis. Studies have demonstrated that ulcerative colitis patients treated with 5-ASA have an overall decrease in the risk of developing colorectal carcinoma. However, the mechanisms underlying 5-ASA-mediated anti-inflammatory and anti-cancer effects are yet to be elucidated. Because peroxynitrite has been critically involved in inflammatory stress and carcinogenesis, this study was undertaken to investigate the effects of 5-ASA in peroxynitrite-induced DNA strand breaks, an important event leading to peroxynitrite-elicited cytotoxicity. Incubation of φX-174 plasmid DNA with the peroxynitrite generator 3-morpholinosydnonimine (SIN-1) led to the formation of both single- and double-stranded DNA breaks in a concentration-dependent manner. The presence of 5-ASA at 0.1 and 1.0 mM was found to significantly inhibit SIN-1-induced DNA strand breaks in a concentration-dependent manner. The consumption of oxygen induced by SIN-1 was found to not be affected by 5-ASA at 0.1-50 mM, indicating that 5-ASA at these concentrations is not involved in the auto-oxidation of SIN-1 to form peroxynitrite. It is observed that 5-ASA at 0.1-1 mM showed considerable inhibition of peroxynitrite-mediated luminol chemiluminescence in a dose-dependent fashion, suggesting that 5-ASA is able to directly scavenge the peroxynitrite. Electron paramagnetic resonance (EPR) spectroscopy in combination with spin-trapping experiments, using 5,5-dimethylpyrroline-N-oxide (DMPO) as spin trap resulting in the formation of DMPO-hydroxyl radical adduct from peroxynitrite, and 5-ASA only at higher concentration (1 mM) inhibited the hydroxyl radical adduct while shifting EPR spectra, indicating that 5-ASA at higher concentrations may generate a more stable free radical species rather than acting purely as a hydroxyl radical scavenger. Taken together, these studies demonstrate for the first time that 5-ASA can potently inhibit peroxynitrite-mediated DNA strand breakage, scavenge peroxynitrite, and affect peroxynitrite-mediated radical formation, which may be responsible, at least partially, for its anti-inflammatory and anti-cancer effects.

Thermolysis of Cp*W(NO)(CH2CMe3)(eta(3)-CH2CHCHMe) (1) at ambient temperatures leads to the loss of neopentane and the formation of the eta(2)-diene intermediate, Cp*W(NO)(eta(2)-CH2=CHCH=CH2) (A), which has been isolated as its 18e PMe3 adduct. In the presence of linear alkanes, A effects C-H activations of the hydrocarbons exclusively at their terminal carbons and forms 18e Cp*W(NO)(n-alkyl)(eta(3)-CH2CHCHMe) complexes. Similarly, treatments of 1 with methylcyclohexane, chloropentane, diethyl ether, and triethylamine all lead to the corresponding terminal C-H activation products. Furthermore, a judicious choice of solvents permits the C-H activation of gaseous hydrocarbons (i.e., propane, ethane, and methane) at ambient temperatures under moderately elevated pressures. However, reactions between intermediate A and cyclohexene, acetone, 3-pentanone, and 2-butyne lead to coupling between the eta(2)-diene ligand and the site of unsaturation on the organic molecule. For example, Cp*W(NO)(eta(3),eta(1)-CH2CHCHCH2C(CH2CH3)2O) is formed exclusively in 3-pentanone. When the site of unsaturation is sufficiently sterically hindered, as in the case of 2,3-dimethyl-2-butene, C-H activation again becomes dominant, and so the C-H activation product, Cp*W(NO)(eta(1)-CH2CMe=CMe2)(eta(3)-CH2CHCHMe), is formed exclusively from the alkene and 1. All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them have been established by X-ray crystallographic analyses. Finally, the newly formed alkyl ligands may be liberated from the tungsten centers in the product complexes by treatment with iodine. Thus, exposure of a CDCl3 solution of the n-pentyl allyl complex, Cp*W(NO)(n-C5H11)(eta(3)-CH2CHCHMe), to I2 at -60 degrees C produces n-C5H11I in moderate yields.

A series of pyridine complexes are prepared of the general form TpW(NO)(PMe3)(pyr) where pyr is either pyridine or a substituted pyridine. Depending on substitution pattern, the pyridine can be either N- or eta2-coordinated, and the role of the pyridine substituents and metal oxidation state in determining this equilibrium is explored. For eta2-pyridine complexes, the substituent pattern and solubility characteristics also determine the ratio of coordination diastereomers. Rates of both intra- and interfacial linkage isomerizations are explored along with the pyridine rotational barrier. This study is supported by DFT calculations and X-ray data and includes characterization of both eta2-pyridine and eta2-pyridinium complexes.

Molybdenacyclobutane complexes can be prepared by reaction of Cp*Mo(NO)(=CHCMe3) (formed spontaneously by loss of neopentane from Cp*Mo(NO)(CH2CMe3)2 (1) under ambient conditions) with cyclic olefins, including cyclopentene, cycloheptene, and cyclooctene. The cyclopentene metallacyclobutane orients the metallacycle bridgehead protons cis to each other. A trans arrangement is observed for the cyclooctene congener, and both cis and trans orientations occur for the cycloheptene species. The reaction of 1 with cyclohexene initially forms a metallacyclobutane that then undergoes an allylic C-H activation to form an allyl-alkyl-coupled product with the concomitant loss of H2. The analogous allyl-alkyl structure is also observed as the thermodynamic product for the reactions of cycloheptene and cyclooctene with 1. The cyclooctene allyl-alkyl compound (5C) can be converted to an eta2-diene complex by heating with pyridine. Alternatively, heating of 5C in the presence of a variety of olefins displaces the diene ligand that can then be isolated in its unbound state.

The isoquinuclidine (2-azabicyclo[2.2.2]octane) core is found in numerous molecules of biological and medicinal importance, including the widely investigated Iboga alkaloids and their related bisindole Cantharanthus alkaloids (Sundberg, R. J.; Smith, S. Q. Alkaloids (San Diego, CA, United States) 2002, 59, 281-386). A diverse range of synthetic methods for the stereoselective construction of this architecture is required for the efficient development of related pharmaceuticals. Here, we report a fundamentally new methodology that constructs the isoquinuclidine core directly from pyridines, using a pi-basic tungsten complex to disrupt the aromatic stabilization of these otherwise inert heterocycles. By this approach, common pyridines are found to undergo stereoselective Diels-Alder reactions with electron-deficient alkenes under mild reaction conditions, thus providing access to a broad range of functionalized isoquinuclidines. Further, by using the common terpene alpha-pinene, a single enantiomer of the tungsten fragment can be isolated and used to provide access to enantio-enriched isoquinuclidines from pyridines.

A total of 21 complexes of CuX (X = Cl, Br, I) with bridging ligand (B = 4,4'-dipyridyl (Bpy), pyrazine (Pyz), quinoxaline (Quin), phenazine (Phz), 1,4-diazabicyclo[2.2.2]octane (DABCO), and hexamethylenetetramine (HMTA)) have been synthesized. The products show two stoichiometries: [CuXB] (type 1) and [(CuX)2B] (type 2). Both types can be obtained for B = Bpy, depending on the conditions of preparation. In these cases, the type 2 stoichiometry is the kinetic product. Type 2 complexes only are found for B = Pyz (X = I), Quin, Phz, DABCO, and HMTA. Type 1 complexes form for Pyz (X = Cl, Br). Thermogravimetic analyses of the complexes reveal the general decomposition trend: 1 --> 2 --> [(CuX)2B(1/2)] --> CuX. The X-ray crystal structure of [CuBr(Pyz)] (type 1) features copper atoms bridged by Br and Pyz, forming 2D sheets of fused rectangular Cu4Br2(Pyz)2 units. The X-ray structure of [(CuI)2(Quin)] (type 2) shows 2D layers composed of [Cu2I2]infinity "stair step" chains which are cross-linked by Quin ligands. A total of 16 complexes of CuXL (L = P(OPh)3) with bridging ligand (B = those above and 1,4-dimethylpiperazine (DMP)) have also been prepared. All of these products, except those of HMTA, are of type 3 formulation, [(CuXL)2B]. The HMTA products have the formula [CuX(HMTA)], type 4. Thermal decomposition of the type 3 and 4 complexes occurs with initial loss of B, L, or both. The X-ray structures of [(CuBrL)2(Bpy)] and [(CuBrL)2(Pyz)] (type 3) reveal 1D chains formed from rhomboidal (LCu)2Br2 units linked by the B ligand. The type 4 structure of [CuBrL(HMTA)] is shown by X-ray to be a simple halide-bridged dimer.

Thirty-nine Thoroughbred and Quarter Horse yearlings were used in two 112-d experiments to determine the effect of lysine and threonine supplementation on growth and development. Yearlings were individually fed three dietary treatments that consisted of a pelleted concentrate containing corn, oats, and soybean meal fed to appetite twice daily and Coastal bermuda grass hay group-fed at a rate of 1 kg/100 kg BW. Three concentrates were tested: (A) basal, (B) basal plus .2% lysine, and (C) basal plus .2% lysine, and .1% threonine. Feed intake, weight, withers height, girth, hip height, body length, and hoof growth (Exp. 1) were recorded every 28 d, and initial and final radiographs taken for estimating bone mineral content. Final croup fat thickness was measured ultrasonically in Exp. 1, and initial and final croup fat measured in Exp. 2. Blood samples were taken every 28 d for determination of serum urea N and protein in Exp. 2. Average daily feed intake (as-fed) was 8.8 +/- .14, 9.0 +/- .13, and 9.2 +/- .13 kg (P < .09), ADG was .57 +/- .02, .64 +/- .02, and .67 +/- .02 kg/d (P < .02), and girth gain was 9.7 +/- .49, 10.1 +/- .46, and 11.3 +/- .47 cm (P < .05) for Treatments A, B, and C, respectively. Gain:feed ratios in Exp. 1 were 70.5, 70.8, and 75.5 g/kg (P > .10) and in Exp. 2 were 61.7, 70.8, and 70.2 g/kg (P < .10) for Treatments A, B, and C, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

During a 9 month period, 50 consecutive children were evaluated by ultrasound to determine the size, location (mesenteric vs para-aortic), number, shape and texture of abdominal lymph nodes in a normal paediatric population. High resolution linear array transducers were used with graded compression. Nodes ranging from 10 to 20 mm were recorded in the majority of subjects. In all cases mesenteric lymph nodes were larger and more numerous than para-aortic nodes. Para-aortic lymph nodes were not seen in isolation.

The problem of teenage spinal cord injury (SCI) secondary to gunshot wounds was observed in a model SCI system. By identifying one factor, 'risk taking', in which the system could intervene, a SCI prevention program was developed that has had major community attention. Hopefully, it will also meet the needs of other communities experiencing interpersonal violence among adolescents.

The results of the overnight 2 mg Dexamethasone Suppression Test administered to 50 manic patients are reported. Twenty-three (46%) cases showed an absence of normal suppression, results which are similar to those seen in endogenous depression and which differ to those of others who have all reported normal suppression in mania. Suppressors and non-suppressors were not shown to differ in the factors of age, weight, polarity or the rated severity of mood.

Catastrophic injuries and illnesses create great financial strains on patients who require lifetime care. Families, health care providers and insurers recognise that individual patient care needs require a closer look at the prudent allocation of health care benefit dollars. Blue Cross Blue Shield of Michigan has initiated an approach to this problem called 'case management'. Two ventilator dependent quadriplegics were discharged home utilising the case management concept. This system provides many advantages for patients. However, the health care team needs to be aware of the drawbacks of the system.

Interpersonal violence with a handgun is the primary cause of spinal cord injuries (SCI) among teenagers in the population served by the Southeastern Michigan Spinal Cord Injury System (SEMSCIS). As part of a community-wide effort to reduce the injury and death rate from acts of violence, SEMSCIS selected the victim, rather than the perpetrator or the sociocultural environment, as its segment of a prevention program. A retrospective study of demographic data, causal statements, medical information from the medical records of 36 injured adolescents, and telephone conversations with the victims identified "risk taking" as the pre-event behavior that had made them vulnerable to violence. This study led to the production of a powerful video, "Wasted Dreams," in which disabled teenagers tell their peers about their injury and how to avoid becoming a victim.

Falls are the major cause of spinal cord injuries in older people. The pattern of injury seen most frequently is that of a central cord syndrome due to cervical hyperextension. The medical records of 58 patients over 50 years of age who sustained a spinal cord injury in a fall were reviewed for circumstances of onset, length of stay and outcomes of rehabilitation. The study identified elderly single or widowed men, and those who use alcohol, as high risk groups.