Exchange Cycle Research Articles

Uncovering through a Mixed Method Lense: The Perceived Leadership Styles and Employees Job Satisfaction in Higher Education

The objectives of this research are to identify leadership styles and job satisfaction among non-academic employees who support the teaching faculty of the University of the Punjab. There are two variables: perceived leadership styles (PLS) and employee job satisfaction (EJS). The quantitative and qualitative methodology was used for an estimated sample size of 300 non-academic employees. Data was analyzed using descriptive analysis and thematic analysis methods. Frequency tables, percentages, means, and standard deviation were used for data presentation and analysis. The study suggested that there was a positive significant relationship between perceived leadership styles and employees’ job satisfaction. The literature stresses the social exchange cycle and reciprocity rules in the relationships of leaders and their members. In this cycle, if the leaders care about their members and if members perceive that the leaders are supportive, they feel satisfied to behave positively, take voluntary extra work of colleagues in time of need, perform better, and help the higher education universities to reach their goals and objectives. If they don’t perceive leaders' support, they don’t care about the educational organization either.

Low-GWP refrigerants in heat pumps: An experimental investigation of the influence of an internal heat exchanger

In heat pumps, the use of refrigerants with a low global warming potential (GWP) gains importance due to increasingly strict regulations regarding their ecological impact. In this regard, hydrocarbons (HCs), hydrofluoroolefins (HFOs), and their mixtures are the most promising options due to their thermodynamic properties. Besides the impact of the refrigerant, the cycle configuration (e.g., basic cycle and internal heat exchanger cycle) strongly influences the efficiency of the heat pump. While the potential of low-GWP refrigerants in internal heat exchanger (IHX) cycle configurations is widely investigated in numerical studies, there is a lack of experimental validation. Therefore, this work experimentally evaluates four HCs (R290, R600a, R436A, R1270) and the HFO R1234yf in comparison to R134a in a brine-water heat pump test bench. The test bench design allows to switch between the basic and IHX cycle, thus, enabling the simultaneous impact evaluation of the cycle configuration and the refrigerant on the performance. In the experiments, R1270 shows the highest efficiency for all operating points followed by R290 in the basic cycle. The IHX cycle improves the efficiency for all refrigerants in comparison to the basic cycle. The zeotropic mixture R436A achieves the highest efficiency improvements of up to 27.5% compared to the basic cycle, whereas the efficiency of the single-component refrigerants increases by 10% on average. Despite the significantly higher improvements of R436A due to the IHX, R1270 still leads to the highest coefficient of performance (COP) of up to 6.6 (B12/W35) in the IHX cycle configuration.

Therapeutic Plasma Exchange in Neurological Conditions: An Observation from the Eastern Part of India.

Therapeutic plasma exchange (TPE) is an extracorporeal process of separation of plasma from the cellular components of blood and its replacement with analogous fluids. This process is effective in treatment of disease conditions from dysregulation of the humoral immune system by removal of various humoral pathogenic substances like antibodies, immune complexes, monoclonal proteins, toxins or cytokine(s) and/or the replenishment of a specific plasma factor. To evaluate major indications of therapeutic plasma exchange in neurological disorders. To identify major complications associated and factors associated with premature cessation of the therapeutic plasma exchange cycle. Materials and Methods: This is a hospital based retrospective study conducted by analyzing medical records of patients, who had undergone therapeutic plasma exchange (TPE) for various neurological disorders at IMS & SUM hospital. Medical records total 118 patients who underwent TPE from January 2016 to December 2021 were analyzed. The demographic data, blood group pattern and indications for TPE were enumerated from the records. Various complications of TPE and reasons for incomplete TPE cycle were documented and analyzed. A total of 508 TPE procedures were performed on 118 patients. In this study 61 patients were male and 57 patients were female. O-blood group was commonest blood group among the patients. GBS is the commonest indication of TPE. 57.6 % of patients could complete all sessions TPE cycle. Blockage of vascular access is the commonest cause of incomplete TPE session. Cramps (33%) and mild transient hypotension (27.1%0 were the commonest complications observed. TPE is a safe and effective treatment option for various immune-mediated neurological disorders and should be considered in managing these disorders.

Plasma-catalytic direct oxidation of methane to methanol over Cu-MOR: Revealing the zeolite-confined Cu2+ active sites

Efficient methane conversion to methanol remains a significant challenge in chemical industry. This study investigates the direct oxidation of methane to methanol under mild conditions, employing a synergy of non-thermal plasma and Cu-MOR (Copper-Mordenite) catalysts. Catalytic tests demonstrate that the Cu-MOR IE-3 catalyst (i.e., prepared by three cycles of ion exchange) exhibits superior catalytic performance (with 51 % methanol selectivity and 7.9 % methane conversion). Conversely, the Cu-MOR catalysts prepared via wetness impregnation tend to over-oxidize CH4 to CO and CO2. Through systematic catalyst characterizations (XRD, TPR, UV–Vis, HRTEM, XPS), we elucidate that ion exchange mainly leads to the formation of zeolite-confined Cu2+ species, while wetness impregnation predominantly results in CuO particles. Based on the catalytic performance, catalyst characterizations and in-situ FTIR spectra, we conclude that zeolite-confined Cu2+ species serve as the active sites for plasma-catalytic direct oxidation of methane to methanol.

Sustainable Production: Integrating Medicinal Plants with Fish Farming in Aquaponics—A Mini Review

Aquaponics, defined as a sustainable technology combining aquaculture and hydroponics, integrates plant and fish production into one system. Aquaponics technology offers several major advantages over conventional methods of raising fish and/or plants. In this system, plants act as a natural biological filter, purifying the water so that the same amount can be used repeatedly. Fish, on the other hand, are a natural source of nutrients. This contributes to the aquaponics system’s substantial economic potential, thanks to its use of virtually free nutrients, dramatically reduced water consumption, and the elimination of filter systems, making this system innovative and sustainable. On the other hand, the use of medicinal plants for the needs of the pharmaceutical, cosmetics, and food industries is often associated with a decrease in their natural reserves. Utilizing aquaponics for the production of medicinal plants could reduce the pressure on these natural reserves. As a result, aquaponics has emerged as one of the most environmentally friendly methods of cultivating plant species. The concept of aquaponics, which evolved from traditional hydroponic systems, has gained worldwide recognition through the effective use of symbiosis. It refers to the coexistence and interaction of different organisms, facilitating their growth and life cycle processes. Unlike hydroponics, which requires the purification of nutrient solutions due to plant waste, aquaponics takes advantage of the natural cycle of waste and nutrient exchange between plants and fish. Fish waste serves as organic fertilizer for the plants, while the plants help purify the water for the fish. This symbiotic relationship not only reduces the environmental impact associated with aquaculture wastewater but also provides a sustainable method of food production. The integrated system reduces infrastructure costs, conserves water, and minimizes the potential for environmental pollution. Furthermore, it provides an opportunity for increased profitability from both crop and fish production. Cultivation of medicinal plants within aquaponic systems can be carried out year-round, offering a continuous supply of valuable pharmacological resources. This review examines suitable medicinal plants for aquaponic cultivation and evaluates their pharmacological benefits to humans.

Plasma-exchange therapy in acute immune-mediated neuropathy: Effects on muscle strength and functional outcomes

Background and objectives. This study explores the impact of plasma exchange therapy (TPE) on muscle strength and functional outcomes in patients with acute immune-mediated neuropathy. Materials and methods. We retrospectively analyzed clinical data from patients diagnosed with acute immune-mediated neuropathy at the Department of Neurology, Bolan University of Medical Sciences, Baluchistan, from January 2016 to December 2021. Results. The study, comprising 141 patients with various neurological disorders, underscores the efficacy of plasma exchange therapy in improving muscle strength and functional outcomes, particularly in Guillain-Barré Syndrome (GBS). Notably, after four weeks of treatment, a significant proportion of patients demonstrated improved mobility, with 51.8% able to walk without assistance. However, despite the positive response to therapy, a small percentage (2.8%) experienced unfavorable outcomes marked by expiration. Additionally, the study identifies significant associations between treatment outcomes and patient characteristics, such as the number of plasma exchange cycles and diagnosis (p <0.05), emphasizing the importance of personalized treatment approaches in managing neurological disorders. Conclusions. Our findings underscore the effectiveness of plasma exchange in enhancing muscle strength and functional outcomes in acute immune-mediated neuropathy, particularly GBS.

Tidally driven porewater exchange and diel cycles control CO2 fluxes in mangroves on local and global scales

Mangrove soils are highly enriched in organic carbon. Tidal pumping drives seawater and oxygen into mangrove soils during flood tide and releases carbon-rich porewater during ebb tides. Here, we resolve semi-diurnal (flood/ebb tides), diel (day/night) and weekly (neap/spring tides) drivers of porewater-derived CO2 fluxes in two mangroves and update global estimates of CO2 emissions building on earlier observations from other sites. Tidal pumping controlled pCO2 variability within the two mangrove creeks. The highest values of pCO2 (2,585–6,856 µatm) and 222Rn (2,315–6,159 dpm m−3) and lowest values of pH (6.8–7.1) and dissolved oxygen (1.7–3.7 mg L−1) at low tides were due to enhanced porewater export. 222Rn and pCO2 in mangrove porewater were 4–15 and 38–41 times greater than surface waters, respectively. pCO2 increased by 50 ± 30 % from high to low tide, 9 ± 22 % from day to night and 57 ± 5 % from neap to spring tide with clear changes in hourly, diel, and weekly time scales. Combining our new estimates with literature data, global porewater-derived (16 sites) and water-atmosphere (52 sites) CO2 fluxes in mangroves would upscale to 45 ± 12 and 41 ± 10 Tg C y−1, respectively. These fluxes represent 25 % of net primary production and are twice as high as the sediment carbon burial rates in global mangroves. Overall, our local observations and global compilation suggest that porewater-derived CO2 exchange is a major but often unaccounted source of CO2 in mangroves. The porewater-derived CO2 can be emitted to the atmosphere or laterally exported to the ocean and should be included in carbon budgets to solve global imbalances.

Enantioselective Self-Assembly of a Homochiral Tetrahedral Cage Comprising Only Achiral Precursors.

How Nature synthesizes enantiomerically pure substances from achiral or racemic resources remains a mystery. In this study, we aimed to emulate this natural phenomenon by constructing chiral tetrahedral cages through self-assembly, achieved by condensing two achiral compounds-a trisamine and a trisaldehyde. The occurrence of intercomponent CH⋅⋅⋅π interactions among the phenyl building blocks within the cage frameworks results in twisted conformations, imparting planar chirality to the tetrahedrons. In instances where the trisaldehyde precursor features electron-withdrawing ester side chains, we observed that the intermolecular CH⋅⋅⋅π forces are strong enough to prevent racemization. To attain enantioselective self-assembly, a chiral amine was introduced during the imine formation process. The addition of three equivalents of chiral amino mediator to one equivalent of the achiral trisaldehyde precursor formed a trisimino intermediate. This chiral compound was subsequently combined with the achiral trisamino precursor, leading to an imine exchange reaction that releasing the chiral amino mediator and formation of the tetrahedral cage with an enantiomeric excess (ee) of up to 75 %, exclusively composed of achiral building blocks. This experimental observation aligns with theoretical calculations based on the free energies of related cage structures. Moreover, since the chiral amine was not consumed during the imine exchange cycle, it enabled the enantioselective self-assembly of the tetrahedral cage for multiple cycles when new batches of the achiral trisaldehyde and trisamino precursors were successively added.

Enantioselective Self‐Assembly of a Homochiral Tetrahedral Cage Comprising Only Achiral Precursors

AbstractHow Nature synthesizes enantiomerically pure substances from achiral or racemic resources remains a mystery. In this study, we aimed to emulate this natural phenomenon by constructing chiral tetrahedral cages through self‐assembly, achieved by condensing two achiral compounds–a trisamine and a trisaldehyde. The occurrence of intercomponent CH⋅⋅⋅π interactions among the phenyl building blocks within the cage frameworks results in twisted conformations, imparting planar chirality to the tetrahedrons. In instances where the trisaldehyde precursor features electron‐withdrawing ester side chains, we observed that the intermolecular CH⋅⋅⋅π forces are strong enough to prevent racemization. To attain enantioselective self‐assembly, a chiral amine was introduced during the imine formation process. The addition of three equivalents of chiral amino mediator to one equivalent of the achiral trisaldehyde precursor formed a trisimino intermediate. This chiral compound was subsequently combined with the achiral trisamino precursor, leading to an imine exchange reaction that releasing the chiral amino mediator and formation of the tetrahedral cage with an enantiomeric excess (ee) of up to 75 %, exclusively composed of achiral building blocks. This experimental observation aligns with theoretical calculations based on the free energies of related cage structures. Moreover, since the chiral amine was not consumed during the imine exchange cycle, it enabled the enantioselective self‐assembly of the tetrahedral cage for multiple cycles when new batches of the achiral trisaldehyde and trisamino precursors were successively added.

Metamorphosis, Mediation, Mannat

In the South Asian discourse of Sufism, or Islamic mysticism, ‘natural’ functions can be transcended and bodily boundaries are permeable. Defying species boundaries, this relational ontology entails a belief in the capacity for bodily transformation, or metamorphosis, from one category of being to another (as from human to nonhuman animal). In turn, both human and animal actors enter into conversation with mediating ‘spirits’. To this day, these religious entanglements, passed down through generations, allow Sufi communities in Bangladesh and Pakistan to protect ‘sacred’ animals at shrines as vital refuges for wildlife species and to make an important contribution to their conservation. The relational dynamics allow for the cultural division between human and non-human life forms (plants, animals, and spirits) to be problematized, and permeable boundaries to be dissolved into liminal and dynamic zones of interaction. Deeply entangled, agents both human and non-human actively participate in shared ritual configurations that take place within and are nourished by a locally embedded Sufi spirituality. Ritual and devotional practices revolve around their intercessory mediation (shafa'at) with the divine, which endows them with spiritual agency, as they engage in cycles of exchange, such as the practice of taking vows (mannat). Within the framework of this Sufi-inspired, locally embedded spirituality, it is possible for animals to be genuine agents, to have spiritual ‘agency’ and to be involved in cycles of exchange.

Transport and inhibition mechanism for VMAT2-mediated synaptic vesicle loading of monoamines.

Monoamine neurotransmitters such as serotonin and dopamine are loaded by vesicular monoamine transporter 2 (VMAT2) into synaptic vesicles for storage and subsequent release in neurons. Impaired VMAT2 function underlies various neuropsychiatric diseases. VMAT2 inhibitors reserpine and tetrabenazine are used to treat hypertension, movement disorders associated with Huntington's Disease and Tardive Dyskinesia. Despite its physiological and pharmacological significance, the structural basis underlying VMAT2 substrate recognition and its inhibition by various inhibitors remains unknown. Here we present cryo-EM structures of human apo VMAT2 in addition to states bound to serotonin, tetrabenazine, and reserpine. These structures collectively capture three states, namely the lumen-facing, occluded, and cytosol-facing conformations. Notably, tetrabenazine induces a substantial rearrangement of TM2 and TM7, extending beyond the typical rocker-switch movement. These functionally dynamic snapshots, complemented by biochemical analysis, unveil the essential components responsible for ligand recognition, elucidate the proton-driven exchange cycle, and provide a framework to design improved pharmaceutics targeting VMAT2.

Myelin oligodendrocyte glycoprotein (MOG) antibody positive disease presenting as acute disseminated encephalomyelitis and unilateral optic neuritis

The autoantibody against myelin oligodendrocyte glycoprotein (MOG-abs) is a recognized biomarker in acquired demyelinating syndromes. The diversity in clinical and neuroimaging phenotypes is still being understood in the paediatric population. The presenting clinical phenotype strongly depends on the age at onset. Acute disseminated encephalomyelitis (ADEM) and ADEM-like phenotypes are common in younger children, but optic neuritis (ON), often bilateral, is predominantly seen in females and older children and or adults.We present a 6.5-year-old boy with a rapid onset encephalopathy due to ADEM and a unilateral longitudinally affected optic neuritis detected on neuroimaging. His serum was positive for MOG-abs but negative for Aquaporin-4 antibodies. His cerebrospinal fluid was negative for oligoclonal bands. He gradually improved following treatment with intravenous high-dose methylprednisolone and five cycles of plasma exchange. Complete clinical recovery was achieved within twelve weeks of admission.Conclusion: Contrary to the usual older age of MOG-ON, and the bilateral involvement, this case illustrates a unilateral ON in a six-year-old boy occurring in conjunction with a MOG-ab positive encephalomyelitis.

Anticancer Effect of Alstonia Scholaris Against the Methyl-Methanesulphonate-Induced Genotoxicity in Human Peripheral Lymphocytes in Vitro

Abstract: Alstonia scholaris is used in various Ayurvedic preparations like Saptaparnasatvadi vati, Saptachadadi vati, Saptachhadadi vati, Saptacchadadi taila, Saptacchadadi kvatha and Saptaparna ghanasara or uses of Alstonia scholaris mainly in Whooping cough, Malaria, Jaundice, Gastric complaint, Headache, Asthma, Stomachache, Wound, Fever and also much effective in all types of cancer. The antigenotoxic potential of Alstonia scholaris extract (AS) was demonstrated on the methyl methanesulphonate (MMS) induced genotoxicity. In vitro studies were carried on human lymphocyte culture. We have used chromosomal aberration (CA), sister chromatid exchange (SCE) and cell cycle kinetics (CCK) with and without S9 mix. as markers in this experiments. Four doses viz., 100, 150, 200, 250 μl/ml per culture were selected and found that Alstonia scholaris extract significantly reduces the frequencies of chromosomal aberration, sister chromatid exchanges and enhances RI in vitro .It was also noticed that the antigenotoxic potential of AS shows dose – response relationship. The results suggest that AS was a potent anticarcinogen may contribute to the cancer prevention.

Chemical residues that originate from a higher education institution in Brazil

In 2018, a research study was conducted at a Public University in Brazil to investigate the quantity of chemical residues produced during laboratory activities in undergraduate engineering courses. Data was collected from control documents maintained by the institution responsible for recording waste quantities. The results showed that 383.2 liters of solutions were generated with varying compositions. Inorganic solutions without heavy metals produced the highest volume of waste, while halogenated organic solutions produced the smallest. The study highlights the need for better waste segregation and disposal methods to reduce laboratory waste. To minimize the environmental impact of laboratory activities, implementing measures such as proper waste storage, waste exchange, recycling, reverse logistics, and life cycle assessment is essential. Educational institutions need to develop better waste management practices to reduce the amount of waste in landfills.

Intra-annual carbon fluxes and resource use efficiency of subtropical urban forests: insights from Chongming Island ecological observatory

Understanding the carbon budget within cities is crucial in the context of carbon peaking and carbon neutrality. This study investigates the carbon source-sink dynamics of urban forest ecosystems using carbon flux observations from the Chongming Island Ecological Observatory in Shanghai. The study aims to reveal the intra-annual variations of carbon fluxes and explore the changes in resource use efficiency of urban forest ecosystems within the framework of the big-leaf model. The results reveal distinct patterns in temperature (Tair), relative humidity (RH), radiation, and vapor pressure deficit (VPD). Diurnal cycles of net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (Reco) exhibit seasonal variations, with higher amplitudes observed from April to September. The observed forest ecosystem acts as a moderate carbon sink (318.47 gC m−2 year−1), with the highest carbon uptake occurring in May and the highest carbon emission in February. During the growing season, the total carbon sink was 225.37 gC m−2, composed of GPP 1337.01 gC m−2 and Reco 1111.64 gC m−2. Water-use efficiency (WUE) and light-use efficiency (LUE) exhibit seasonal variations, while carbon-use efficiency (CUE) declines after May. These findings contribute to our understanding of urban forest carbon dynamics and their potential role in carbon management strategies.

Inverse exchange bias and training effect in Gd2Co0.5Mn1.5O6 with negative magnetization

The present experiments indicate that the phenomena of inverse exchange bias and negative magnetization are observed simultaneously in Gd2Co0.5Mn1.5O6 below the ferrimagnetic compensation point Tcomp. The training effect confirms the intrinsic nature of the inverse exchange bias and reveals that the frozen spins relax more slowly than the rotatable spins according to the fitting of exchange bias field (HEB) vs cycle loops (n) curve. The amplitude of HEB varies inversely with the cooling field Hcool and the inverse exchange bias is found to remain up to 50 kOe. The observed exchange bias is argued to be due to the fact that the inverse ferromagnetic moments below Tcomp can be flipped by adjusting the amplitude or direction of the magnetic field during the M(H) hysteresis loop measurement. The manipulability of the negative magnetization state is demonstrated by the remanent magnetization and magnetic switching measurements.

Molecular dynamics simulation of RAC1 protein and its de novo variants related to developmental disorders

Neurodevelopmental disorders (NDDs) are conceptualized as childhood disability, but it has increasingly been recognized as lifelong neurological conditions that could notably impact adult functioning and quality of life. About 1%-3% of the general population suffers from NDDs including ADHD, ASD, IDD, communication disorders, motor disorders, etc. Studies suggest that Rho GTPases are key in neuronal development, highlighting the importance of altered GTPase signaling in NDDs. RAC1, a member of the Rho GTPase family, plays a critical role in neurogenesis, migration, synapse formation, axon growth, and regulation of actin cytoskeleton dynamics. We performed 6µs all-atom molecular dynamics simulation of native RAC1 (PDB: 3TH5) and three-point mutations (C18Y, N39S, and Y64D) related to developmental disorders to understand the impact of mutations on protein stability and functional dynamics. Our analysis, which included root mean square deviation (RMSD), root mean square fluctuation (RMSF), solvent accessible surface area (SASA), radius of gyration (Rg), free energy landscape (FEL), and principal component analysis (PCA), revealed that the N39S and Y64D mutations induced significant structural changes in RAC1. These alterations primarily occurred in the functional region adjacent to switch II, a region crucial for complex conformational rearrangements during the GDP and GTP exchange cycle. Communicated by Ramaswamy H. Sarma

Shapley–Scarf Housing Markets: Respecting Improvement, Integer Programming, and Kidney Exchange

In a housing market of Shapley and Scarf, each agent is endowed with one indivisible object and has preferences over all objects. An allocation of the objects is in the (strong) core if there exists no (weakly) blocking coalition. We show that, for strict preferences, the unique strong core allocation “respects improvement”—if an agent’s object becomes more desirable for some other agents, then the agent’s allotment in the unique strong core allocation weakly improves. We extend this result to weak preferences for both the strong core (conditional on nonemptiness) and the set of competitive allocations (using probabilistic allocations and stochastic dominance). There are no counterparts of the latter two results in the two-sided matching literature. We provide examples to show how our results break down when there is a bound on the length of exchange cycles. Respecting improvements is an important property for applications of the housing markets model, such as kidney exchange: it incentivizes each patient to bring the best possible set of donors to the market. We conduct computer simulations using markets that resemble the pools of kidney exchange programs. We compare the game-theoretical solutions with current techniques (maximum size and maximum weight allocations) in terms of violations of the respecting improvement property. We find that game-theoretical solutions fare much better at respecting improvements even when exchange cycles are bounded, and they do so at a low efficiency cost. As a stepping stone for our simulations, we provide novel integer programming formulations for computing core, competitive, and strong core allocations. Funding: P. Biró gratefully acknowledges financial support from the Hungarian Scientific Research Fund, OTKA [Grant K143858] and the Hungarian Academy of Sciences [Grant LP2021-2]. F. Klijn gratefully acknowledges financial support from AGAUR–Generalitat de Catalunya [Grants 2017-SGR-1359 and 2021-SGR-00416] and the Spanish Agencia Estatal de Investigación [Grants ECO2017-88130-P and PID2020-114251GB-I00] (funded by MCIN/AEI/10.13039/501100011033) and the Severo Ochoa Programme for Centres of Excellence in R&D (Barcelona School of Economics) [Grant CEX2019-000915-S]. Research visits related to this work were financed by COST Action [Grant CA15210 ENCKEP], supported by COST (European Cooperation in Science and Technology), http://www.cost.eu/ .

Hyporheic exchange and nitrogen cycle processes under the dual effects of flooding and heterogeneous streambed

In this study, we investigated the effects of media heterogeneity and flood processes on hyporheic exchange and nitrogen cycle processes in hyporheic zone adjacent to a natural in-stream gravel bar. We conducted field experiments and set a reactive transport model of surface-groundwater exchange based on the monitoring results. The flood process is obtained based on field monitoring, and the heterogeneous medium field is constructed using the SAR3DC method based on in-site experiment results. The results showed that both the heterogeneity of the medium and the flood process can enhance the spatial variability of velocity distribution, resulting in an increase of exchange flux, a decrease in lag time, and an extension of the migration path. For heterogeneous media, it is easier to form specific channels for high velocity flow, and the flow velocity within them is more sensitive to changes in media and hydrodynamic conditions, the direction of hyporheic exchange can be reversed in some specific channels. For the nitrogen cycle processes, the heterogeneous medium condition determines the source-sink functions and the direction of nitrate nitrogen reduction in hyporheic zone by providing a wider reaction space for reactants, reducing the lag time to 1/40 and increasing the migration path by 4 times. The flood process can increase the infiltration amounts of reactants by 5 times and reduce the lag time (time of particle entry into the hyporheic zone to migrate out) to 1/6. In general, under the effects of media heterogeneity and flood processes, the reaction rates and nitrate nitrogen reduction rates during the nitrogen cycle processes are decreasing and the hyporheic zone will face greater pollution risks.

Bleeding Diathesis Secondary to a Heparin-Like Anticoagulant in a Patient with Multiple Myeloma—A Case Report and Review of Literature

AbstractMultiple myeloma (MM) is a clonal plasma cell disorder that commonly presents with anemia, renal failure, hypercalcemia, and lytic bone lesions. MM is also frequently associated with thrombotic complications; however, it may rarely present with bleeding diathesis. We report a case of a 42-year-old gentleman with relapsed immunoglobulin G lambda MM who presented with epistaxis, gingival bleeding, and oozing at the venepuncture site. Routine tests of coagulation revealed a prolonged prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin time. The PT and aPTT failed to correct with pooled normal plasma and the patient was thus diagnosed to have an acquired heparin-like anticoagulant (HLAC). The source of this HLAC has long been debated, but recent data have demonstrated that this HLAC may be the paraproteins produced by the malignant plasma cells. The patient was treated with intravenous protamine sulfate, repeated cycles of plasma exchange, and a daratumumab-based quadruplet regimen but eventually succumbed to an intracranial hemorrhage. HLAC is a rare but potentially fatal complication of MM that must be considered when patients with MM present with bleeding diathesis.