Volume Shifts Research Articles

Assessing the Competitiveness: Afghanistan’s Fresh Grapes Export Performance in the Global Market

This study assesses Afghanistan’s fresh grapes export competitiveness using methods like CAGR for growth, CDVI for instability, and RCA/RSCA for comparative advantage. It also applied the NPC to evaluate price competitiveness, Markov Chain Analysis to track export patterns, and the Bai-Perron test to identify structural breaks, providing a comprehensive analysis of Afghanistan's global market position during 2008 to 2023. Fresh grapes, was one of the important components of Afghanistan’s agricultural exports, grew considerably in both quantity and value, though their export performance was marked by notable instability. The study highlighted that, Afghanistan had moderate competitiveness in the world market, aided by favorable climatic conditions. However, a low NPC suggested limited trade protection, as domestic prices for Afghan grapes remained below international prices. Comparative analyses showed that, while Chile’s export volumes were declined and value growth held steady due to rising prices. Peru achieved robust export growth despite moderate instability. Italy focused on high quality grapes production primarily for domestic consumption, ensuing with low instability. Pakistan emerged as the most consistent market for Afghan fresh grapes, showed a steady demand that supported Afghanistan’s competitive position in regional trade. Structural breaks in 2015 and 2019 found export volume shifts, with an initial increase from better market access, followed by a decline due to COVID-19. Since 2015, export values declined due to market constraints and economic factors, but recovered strongly with favorable weather and government policy adjustments.

Don’t count your chickens before they hatch: Conceptualizing and exploring deviations from polls during public health app releases

Policymakers often rely on pre-release polls to design and deploy public health apps. However, these apps often fail to realize their full potential because the actual size of the user population is significantly lower than expected, and the characteristics of those who use the app differ from those previously inclined to install it. This study aims to understand the success of public health apps by examining shifts between expected and actual user populations during app releases. Rooted in the context of public health apps, we identify factors that potentially intervene in the time between an initial poll of intentions and actual behavior. We delineate two deviations between stated installation intentions in polls and actual installations at an individual level, which have been commingled in literature thus far: inclined nonusers (Type I deviation) and disinclined users (Type II deviation). By introducing this distinction, we hypothesize that app releases can suffer from (1) a volume shift, which results in overly optimistic expectations of user numbers, and (2) a profile shift, which results in biased expectations of user profiles. Using data from a multi-wave survey, we find evidence for the postulated deviations. Our findings also unveil how contextualized factors from the health belief model can explain the occurrence and extent of these deviations. The findings contribute to information systems research that aims to predict technology adoption based on behavioral intentions. The results also offer actionable guidance for policymakers who rely on stated intentions in polls to tackle public health issues.

Utilizing Paleoclimate Data to Analyze the Relationship Between Climate Change and Human Activities

Our research aims at finding the relationship between climatic cycle-changes and the human activities in ancient China. Most climatic changes show shifts in the precipitation volume and alternations between warm and cold periods. Through other research findings, we find the precipitation volume is closely connected with alternations of warm and cold periods. This report presents a linear comparison between the population of ancient China and the east Asia climate variables and chooses tree rings as the main indicator of the paleo-climate. Through the literature review and the data analysis, we find that (1) The dominant climate pattern in East Asia is East Asia Summer Monsoon system, causing centennial scaled climate periodicities, affecting the ecosystem and the society. (2) There are certain cycles of climate change, in which the warm period and the cold period have a certain influence on the population change. (3) The precipitation has a certain correlation with the population change. However, single temperature and precipitation cannot directly affect the population change, but also need to be combined with social and historical factors specific analysis.

Improving the discharge performance of aqueous Mg-air battery using dicarboxylic acid additives

The aqueous Mg-air battery has promising applications in energy storage system. To improve the discharge performance of the Mg anode, four dicarboxylic acids including oxalic acid, malic acid, succinic acid, adipic acid are used as electrolyte additive for the aqueous Mg-air battery. The influence of the four selected additives and their reaction mechanism are systematically investigated by hydrogen evolution, electrochemical experiments (OCP, half/full-cell test, EIS), SEM, XRD, XPS and DFT calculations. The experiment results demonstrate that the dicarboxylic acid electrolyte additive can active the Mg anode evidently by increasing the hydrogen evolution volume and negative shift of discharge potentials. The surface morphology and the chemical composition analyses demonstrate that the four selected additives can form soluble complexes with Mg2+. The oxalic acid is the best electrolyte additive among the four dicarboxylic acids. The chelating ability of the additives and the pH of the electrolyte both affect the discharge performance of the Mg anode. The mechanism by which the dicarboxylic acids additives improve the discharge performance of the Mg anode is further proved by DFT calculations. It is the soluble Mg2+ complex (MgL, L: dicarboxylate) formed between the additives and the Mg anode that inhibit the formation of the corrosion products and promote the dissolution of the Mg anode, thus enhance the discharge performance of the Mg anode.

Midface Projection Using Biostimulatory Poly- l -Lactic Acid Injectable Implant: A Subgroup Analysis of the Cheek Wrinkle Trial.

Correction of cheek wrinkles using poly- l -lactic acid (PLLA-SCA) was demonstrated in a 12-month study. This analysis assessed change from baseline in lifting effect of PLLA-SCA using a 3D camera to provide additional quantified data. Subjects received PLLA-SCA (reconstituted in 8 mL of sterile water + 1 mL of 2% lidocaine) in both cheeks or no treatment (control). Assessments included the Galderma Cheek Wrinkle Scale (GCWS), aesthetic improvement, and 3D photography. In subjects with severe GCWS at baseline, Canfield software analyzed 3D images for change from baseline in midface volume projection and volume change of both cheeks at Month 9. The primary study showed a statistically significant higher at-rest GCWS responder rate at Month 12 for PLLA-SCA, 71.6%, versus control, 26.1% ( p < .0001). In this Month 9 analysis, mean midface volume projection demonstrated a positive volume shift for PLLA-SCA (left: 0.45 mm; right: 0.34 mm; n = 46) versus control (left: 0.25 mm; right: -0.01 mm; n = 21). Midface volume and max projection changes for PLLA-SCA were +4.88 mL/+1.62 mm (left), +2.84 mL/+1.12 mm (right) versus +0.26 mL/+0.34 mm (left), +0.68 mL/+0.37 mm (right) for control. Poly- l -lactic acid-treatment of subjects with severe GCWS had a clinically meaningful lifting effect in both cheeks (positive volume shift, positive volume change, and max projection) in the midface. NCT04124692.

Plasma Volume Shifts and Acid–Base Balance After a Single Bout of Resistance Training

Abstract Purpose Changes in plasma volume (PV), acid–base status and ventilation have rarely been investigated in relation to resistance training (RT). This study aimed to investigate the effect of a single set of exhaustive leg press exercise on these basic physiological parameters in an integrated manner. Methods Twenty-seven male individuals (27.1 ± 4.1 years, 1.82 ± 0.62 m, 84.4 ± 12.5 kg, BMI: 25.4 ± 3.0 k/gm2) performed a single set leg press exercise during which hemoglobin concentration ([Hb]), hematocrit (Hct), pH, oxygen (pO2) and carbon dioxide partial pressures (pCO2), hydrogen carbonate concentration ([HCO3−]), standard base excess (SBE) and lactate concentration ([La−]) were determined. Total buffer capacity was calculated based on pH, [HCO3−] and pCO2. Results Mean PV decreased by 559 ± 230 mL (13.7%). As a result, arterial oxygen content was significantly increased due to hemoconcentration (P &lt; 0.001). At exhaustion, pH (7.30 ± 0.06), [HCO3−] (18.6 ± 2.0 mmol/L) and SBE (− 6.6 ± 2.4 mmol/L) were all significantly decreased (P &lt; 0.0001). The pCO2 first remained unchanged (39.4 ± 4.3 mm Hg) but demonstrated a significant decrease one-minute post-exercise (34.4 ± 4.2 mmHg), indicating metabolic acidosis with respiratory compensation, which was maintained until t+15. Non-bicarbonate buffering remained constant during recovery while the respiratory component steadily increased until 15-min post-exercise (50.2 mmol/L per pH). Conclusion PV shifts following a single set of leg press exercise improve post-exercise arterial oxygen content. The moderate metabolic acidosis was not compensated during exercise because of restricted breathing but partly compensated during the following 15-min recovery period. The respiratory compensation as part of the bicarbonate buffering made up 50% of total buffer capacity in the course of recovery.

Predicting noise for full-scale distributed propulsion aircraft by synthesizing subscale data with existing prediction tools

Future projections of the economic impact of Urban Air Mobility (UAM) or Advanced Air Mobility (AAM) are bold with global GDP increases ranging from billions to trillions over the next few decades. While the potential opportunities are vast, there will be a paradigm shift in the sheer volume of flights at lower altitudes near populated communities. While there is still debate on the initial markets, there is a strong consensus that these aircraft must not appreciably contribute to the existing soundscape and ideally would be imperceptible in most cases. The novel designs of many distributed propulsion aircraft are challenging the existing noise prediction tools that were primarily built around propellers, jet aircraft, and rotorcraft. This paper will present a summary of recent research efforts on synthesizing subscale experimental acoustics measurement data with noise propagation tools to compute community noise exposure on the ground for different full-scale vehicle configurations and flight profiles. The benefits, drawbacks, and limitations of each data source will be discussed along with suggestions for how to improve the prediction methods and models by synthesizing multiple data sets.

Dual Modification for Low-Strain Ni-Rich Cathodes Toward Superior Cyclability in Pouch Full Cells.

Rapid capacity fading, interfacial instability, and thermal runaway due to oxygen loss are critical obstacles hindering the practical application and commercialization of Ni-rich cathodes (LiNi0.8Co0.1Mn0.1O2, NCM811). Herein, a Sn4+/F- codoping and LiF-coated Ni-rich cathode, denoted as NCM811-SF, is structurally fabricated that demonstrates very high cyclic and thermal stabilities. The introduction of Sn4+ regulates the local electronic structure and facilitates the conversion of the layered structure into a spinel phase; F- captures lithium impurities to form LiF coatings and forms TM-F bonds to reduce Ni/Li disordering. The compositionally complex codoping strategy reduces the internal structure strain, inhibits the Li+/Ni2+ intermixing during cycling and degradation of the nanoscale structure, and further improves the thermal stability and the crystal structure. The cathodic electrode showed a little volume shift at 2.8-4.5 V, which significantly decreased lattice flaws and fractures generated by local strain, based on detailed analyses performed using COMSOL simulations, X-ray diffraction, and scanning transmission electron microscopy. Benefiting from this, after 300 cycles, our as-prepared NCM811-SF cathode maintains 85.4% of its initial capacity at 4.5 V and has an excellent reversible capacity equal to 169 mAh·g-1 at 1 C. In addition, the NCM811-SF/graphite cell in a pouch-type complete cell retained 94.8% of its starting capacity following 500 cycles. These findings underscore the effectiveness of introducing the Sn-O and TM-F bonds in improving the durability and electrochemical efficiency of the cathode material, which makes it a good choice for high-efficiency Li-ion batteries.

Potential US Health Care Savings Based on Clinician Views of Feasible Site-of-Care Shifts

Shifting care to alternative sites when clinically appropriate may be associated with reduced US health care spending, improved access, and, in some cases, improved care outcomes. To fill 2 main gaps in the current literature on site-of-care shifts: (1) understanding the clinician perspective on appropriateness of alternative care sites, given the central role they play in referrals and patient trust and (2) considering all potential sites where care could shift and calculating net savings potential. In this survey study, physicians (MDs and DOs), nurse practitioners, physician assistants, nurse anesthetists, radiology and imaging technicians, and psychologists were surveyed from September 17 to November 22, 2021, about potential shifts of care from the hospital setting to alternative sites. Participants were selected by the survey firm Intellisurvey to provide broad representation across all specialties of interest. A minimum of 34 clinicians responded to each question. Data were analyzed from April 2022 through October 2023. More than 5000 individual diagnostic and procedural codes were reviewed and sorted into 312 distinct care activities by an expert panel of physicians. Survey respondents were then provided with the 2019 claims-based distribution across sites of care for each care activity and were asked, "based on your clinical judgment, what portion of [care activity] could safely occur in each of the following sites of care, without compromising clinical outcomes?" Based on clinician-reported distributions, the total potential shift of volume from hospital-based settings to alternative sites and the associated net savings were estimated. Survey respondents included 1069 practicing clinicians (386 female [36.1%]; mean [SD] years since residency of physicians, 21.0 [9.7] years; mean [SD] age of nonphysicians, 45.3 [9.4] years) across specialties, all of whom practiced more than 20 clinical hours per week. There were 794 physicians (74.3%), and the remaining 275 respondents were midlevel professionals, such as physician assistants. Among 312 care activities surveyed, respondents indicated that 10.3 percentage points (95% CI, 10.0-10.5 percentage points) of commercial and 10.9 percentage points (95% CI, 10.7-11.1 percentage points) of Medicare volume currently taking place in hospital-based settings could shift to alternative sites with today's technology without compromising clinical outcomes. Across the entire US health care system, these shifts could be associated with a reduction in overall health care consumption spending ($3 562 339 000 000 000) by approximately $113.8 billion ($113 767 446 087 174 [3.2%]) to $147.7 billion ($147 661 672 284 263 [4.1%]) annually. In this study, a substantial net savings opportunity was estimated. However, realizing this potential will require ongoing alignment among organizations, clinicians, and policymakers to overcome barriers to these shifts.

Impact of dissolution and precipitation on pore structure in CO2 sequestration within tight sandstone reservoirs

Complex physical and chemical reactions during CO2 sequestration alter the microscopic pore structure of geological formations, impacting sequestration stability. To investigate CO2 sequestration dynamics, comprehensive physical simulation experiments were conducted under varied pressures, coupled with assessments of changes in mineral composition, ion concentrations, pore morphology, permeability, and sequestration capacity before and after experimentation. Simultaneously, a method using NMR T2 spectra changes to measure pore volume shift and estimate CO2 sequestration is introduced. It quantifies CO2 needed for mineralization of soluble minerals. However, when CO2 dissolves in crude oil, the precipitation of asphaltene compounds impairs both seepage and storage capacities. Notably, the impact of dissolution and precipitation is closely associated with storage pressure, with a particularly pronounced influence on smaller pores. As pressure levels rise, the magnitude of pore alterations progressively increases. At a pressure threshold of 25 MPa, the rate of change in small pores due to dissolution reaches a maximum of 39.14%, while precipitation results in a change rate of −58.05% for small pores. The observed formation of dissolution pores and micro-cracks during dissolution, coupled with asphaltene precipitation, provides crucial insights for establishing CO2 sequestration parameters and optimizing strategies in low permeability reservoirs.

Encapsulation hierarchical bimetallic oxide with flexible electrospinning carbon nanofibers for efficient capacitive deionization

Water scarcity, an intensifying issue, has spurred extensive research into the development of sophisticated freestanding pseudocapacitive electrode materials. Characterized by their precise morphology, intricate mechanics, and superior desalination capabilities, these materials are revolutionizing water treatment technologies. However, their broad adoption is hampered by complex fabrication processes and the necessity for various unique components. Herein, the paper introduces a streamlined method combining electrospinning and carbonization to produce a freestanding nitrogen-doped carbon nanofiber encapsulating manganese cobalt oxide (MCO) nanoparticles for desalination purposes. The approach significantly enhances interfacial interactions, mitigates volume shifts during sodium ion adsorption and desorption, and strengthens interfacial stability. Benefiting from its structural and compositional merits, the optimal MCO-1.0 electrode showcases exceptional electrochemical attributes. It achieves an impressive desalination efficiency (34.68 mg g−1), swift capacitive deionization rate (0.58 mg g−1 min−1), and superior cyclic durability. The study enhances our understanding of freestanding carbon fibers encapsulated with metal oxide nanoparticles, a key step toward developing robust electrodes for industrial applications.

Characterization of internal jugular vein region-specific distension and flow patterns during progressive volume shifting.

Blood volume shifts during postural adjustment leads to irregular distension of the internal jugular vein (IJV). In microgravity, distension may contribute to flow stasis and thromboembolism, though the regional implications and associated risk remain unexplored. We characterized regional differences in IJV volume distension and flow complexity during progressive head-down tilt (HDT) (0°, -6°, -15°, -30°) using conventional ultrasound and vector flow imaging. We also evaluated low-pressure thigh cuffs (40 mmHg) as a fluid shifting countermeasure during -6° HDT. Total IJV volume expanded 139±95% from supine (4.6±2.7 mL) to -30° HDT (10.3±5.0 mL). Blood flow profiles had greater vector uniformity at the cranial IJV region (P<0.01) and became more dispersed with increasing tilt (P<0.01). Qualitatively, flow was more uniform throughout the IJV during its early flow cycle phase, and more disorganized during late flow phase. This disorganized flow was accentuated closer to the vessel wall, near the caudal region, and during greater HDT. Low-pressure thigh cuffs during -6° HDT decreased IJV volume at the cranial region (-12±15%; P<0.01) but not the caudal region (P=0.20), although flow uniformity was unchanged (both regions,P>0.25). We describe a distensible IJV accommodating large volume shifts along its length. Prominent flow dispersion was primarily found at the caudal region, suggesting multi-directional blood flow. Thigh cuffs appear effective for decreasing IJV volume but effects on flow complexity are minor. Flow complexity along the vessel length is likely related to IJV distension during chronic volume shifting and may be a precipitating factor for flow stasis and future thromboembolism risk.

Microcirculatory depth of focus measurement shows reduction of tissue edema by albumin resuscitation in burn patients

BackgroundSevere burns induce volume shifts via capillary leaks, eventually requiring massive fluid resuscitation and promoting tissue edema. Albumin may help to mitigate the edema, thereby improving perfusion. This study shows that sublingual microcirculation measurements can quantify both tissue perfusion and edema. MethodsThis prospective observational study was conducted between November 2018 and December 2019 in the intensive care unit of Maasstad Hospital Burn Center, Rotterdam, The Netherlands. Patients with severe burns affecting >15% of the total body surface area were included. Fluid management was conducted in accordance with the Parkland formula. Albumin (20%) was administered at a rate of 0.5 mL/(kg·h), starting 12 h after the burn incident. Alterations in the sublingual microcirculation, including capillary perfusion and density, were measured at admission (T0) and at 4 h (T4) and 12 h (T12) after admission. Sublingual depth of focus (DOF) of the microcirculation was used to quantify the tissue edema. ResultsNine patients were recruited with a mean total body surface area of 36% ± 23%. By T12, a median of 4085 mL (interquartile range [IQR]: 3714–6756 mL) of crystalloids and 446 mL (IQR: 176–700 mL) of 20% albumin were administered. The DOF increased significantly after crystalloid administration (T4 vs. T0, mean difference [MD]=27.4 µm, 95% confidence interval [CI]: 3.4 to 50.9, P=0.040). Following albumin administration, DOF significantly decreased (T12 vs. T4, MD=-76.4 µm, 95% CI: -116.6 to -36.1, P=0.002). Total vessel density decreased significantly with crystalloid administration (T4 vs. T0, MD=-3.5 mm/mm2, 95% CI: -5.7 to -1.4, P=0.004) but increased after albumin administration (T12 vs. T4, MD=6.2 mm/mm2, 95% CI: 3.2 to 9.3, P=0.001). ConclusionSublingual microcirculation measurement of DOF and other parameters provide a valuable tool for the assessment of tissue perfusion and edema in patients with severe burns. Further investigation is required to evaluate the role of albumin in increasing microcirculatory convection and reducing tissue edema.

Influence of Intraoperative Fluid Management on Postoperative Outcome and Mortality of Cytoreductive Surgery for Advanced Ovarian Cancer-A Retrospective Observational Study.

Background: The surgical treatment of advanced ovarian cancer is associated with extensive tissue trauma, prolonged operating times and a considerable volume shift. It, therefore, represents a challenge for anaesthesiological management. Aim: The aim of this single-centre, retrospective, observational study was to investigate whether intraoperative extensive volume supply influences postoperative outcomes and long-term survival. Methods: The study included 73 patients with a mean (SD) age of 63 (13) years who underwent extensive tumour-reducing surgery for ovarian cancer between 2012 and 2015. The effect of the intraoperative fluid balance on postoperative complications, such as anastomotic insufficiency or pleural effusions, was investigated using logistic regression. Further, the influence of fluid balance, lactate and creatinine levels on 5-year survival was analysed in a Cox regression model. Associations between anaesthesia time and the intraoperative fluid balance were examined using Spearman's rank correlation coefficients. Results: The mean (SD) postoperative fluid balance in the considered patient cohort was 9.1 (3.4) litres (l) at a mean (SD) anaesthesia time of 529 (106) minutes. Cox regression did not reveal a statistically significant effect of the fluid balance, but it did reveal a statistically significant association between the lactate level 24 h following surgery and the 5-year survival (HR [95%-CI] fluid balance: 0.97 [0.85, 1.11]; HR [95%-CI] lactate: 1.79 [1.24, 2.58]). According to logistic regression, the intraoperative fluid balance was associated with an increased chance of postoperative complications in the considered patient cohort (OR [95%-CI] 1.28 [1.1, 1.54]). Conclusions: We could not detect a negative impact of an increased fluid balance on 5-year survival, but a negative impact on postoperative complications was found in our patient cohort.

Impact of COVID-19 on e-government: a pilot study of Poland

ABSTRACT Catastrophic events like COVID-19 cause substantial material losses and significant harm to the public. However, such events may also accelerate socioeconomic developments such as increased digitalization of economic and societal activities, including e-government services. These services become especially critical in crisis situations , providing a vehicle for administrative responses and ensuring social and economic functioning. This paper reports on a pilot study on the impact of COVID-19 on the demand for and the provision of e-government services in a municipality in Poland. Interviews with city administrators and technical staff involved in providing e-government services during COVID-19 are the primary data sources. Issues identified relate to changes in work regulations, adjustments to operations, shifts in volume and types of services, and changes in employee attitudes and behaviors. Employing focusing event theory in interpreting the results, this paper contributes to the literature on information and communication technologies, especially e-government in local administrations.

Acute-to-chronic subdural hematoma: radiographic and clinical progression from acute subdural hematoma

Introduction: The pathogenesis of chronic subdural hematoma (CSDH) has not been completely understood. However, different mechanisms can result in space-occupying subdural fluid collections, one pathway can be the transformation of an original trauma-induced acute subdural hematoma (ASDH) into a CSDH. Materials and Methods: All patients with unilateral CSDH, requiring burr hole trephination between 2018 and 2023 were included. The population was distributed into an acute-to-chronic group (group A, n = 41) and into a conventional group (group B, n = 282). Clinical and radiographic parameters were analyzed. In analysis A, changes of parameters after trauma within group A are compared. In analysis B, parameters between the two groups before surgery were correlated. Results: In group A, volume and midline shift increased significantly during the progression from acute-to-chronic (p < 0.001, resp.). Clinical performance (modified Rankin scale, Glasgow Coma Scale) dropped significantly (p = 0.035, p < 0.001, resp.). Median time between trauma with ASDH and surgery for CSDH was 12 days. Patients treated up to the 12th day presented with larger volume of ASDH (p = 0.012). Before burr hole trephination, patients in group A presented with disturbance of consciousness (DOC) more often (p = 0.002), however less commonly with a new motor deficit (p = 0.014). Despite similar midline shift between the groups (p = 0.8), the maximal hematoma width was greater in group B (p < 0.001). Conclusion: If ASDH transforms to CSDH, treatment may become mandatory early due to increase in volume and midline shift. Close monitoring of these patients is crucial since DOC and rapid deterioration is common in this type of SDH.

Cerebral microstructural alterations in Post-COVID-condition are related to cognitive impairment, olfactory dysfunction and fatigue

After contracting COVID-19, a substantial number of individuals develop a Post-COVID-Condition, marked by neurologic symptoms such as cognitive deficits, olfactory dysfunction, and fatigue. Despite this, biomarkers and pathophysiological understandings of this condition remain limited. Employing magnetic resonance imaging, we conduct a comparative analysis of cerebral microstructure among patients with Post-COVID-Condition, healthy controls, and individuals that contracted COVID-19 without long-term symptoms. We reveal widespread alterations in cerebral microstructure, attributed to a shift in volume from neuronal compartments to free fluid, associated with the severity of the initial infection. Correlating these alterations with cognition, olfaction, and fatigue unveils distinct affected networks, which are in close anatomical-functional relationship with the respective symptoms.

Bulk and interfacial thermodynamics of ammonia, water and their mixtures

Ammonia is a promising energy carrier for the green transition, but its hygroscopicity and toxicity necessitate in-depth understanding of its interaction with water. This work examines the bulk and interfacial thermodynamics of the ammonia–water system. Parameters for three equations of state are fitted to experimental data and compared to parameters from literature: PC-SAFT, Cubic Plus Association and Peng–Robinson. Peng–Robinson stands out as most accurate for bulk thermodynamics. Introducing a temperature-dependent volume shift for water with Peng–Robinson yields a highly accurate model without introducing problematic inconsistencies, with errors of 0.05% for saturation pressures, and 0.5% for liquid densities. For the mixture, Peng–Robinson with a two-parameter Huron–Vidal mixing rule reproduces measurements mostly within their uncertainties, whereas the standard mixing rules for PC-SAFT and CPA are less accurate. A literature review of surface tension measurements of ammonia–water mixtures reveals that accurate measurements exist only at ambient temperature. We apply density gradient theory and density functional theory based on PC-SAFT, finding that both models fail at reproducing qualitative features of the surface tensions and adsorptions of dilute solutions of aqueous ammonia. Whereas bulk properties are well characterized, understanding and describing the interfacial thermodynamics of the ammonia–water system demands more work both on the experimental and modeling side.

Assessment of Masseter Volume and Postoperative Stability After Orthognathic Surgery in Patients With Skeletal Class III Malocclusion With Facial Asymmetry.

This study aimed to evaluate the effect of orthognathic surgery on masseter volume in patients with skeletal Class III malocclusion with facial asymmetry and the effect of masseter volume on stability in orthognathic surgery. This research studied 16 patients with Class III malocclusion with facial asymmetry who received combined orthodontic-orthognathic treatment and underwent craniofacial computed tomography (CT) before (T0), 2 weeks after (T1), and 6 months after (T2) surgery. Three-dimensional (3D) CT images were retrospectively analyzed, using 3D volume reconstruction to obtain the masseter volume and examine the impact of the masseter volume on stability in orthognathic surgery. A statistically significant difference ( P < 0.05) in the volume of the masseter was found up to 6 months after orthognathic surgery compared with the preoperative period, and the reduction in the masticatory muscle volume on the lengthened side is greater than on the shortened side ( P < 0.05). The volume of both masseters differed according to facial asymmetry, and the difference was significantly reduced after orthognathic surgery ( P < 0.05). During the period time (T1-T2), cephalometric maxillary marker points were not significantly different ( P > 0.05), and mandibular marker points were significantly anteriorly shifted ( P < 0.05). There was an association between the masseter volume and anterior shift of point B (R > 0.5, P < 0.05), the upward and anterior shifts of the gonion point differed between the lengthened and shortened sides ( P < 0.05). The size of the masseter becomes smaller 6 months after orthognathic surgery, and orthognathic surgery improves both bone and soft tissue symmetry. A larger sagittal relapse of mandibular setback occurred in patients with greater masseter volume. Considering these alterations may be helpful in planning orthognathic surgery.

Rural Hospitals Experienced More Patient Volume Variability Than Urban Hospitals During The COVID-19 Pandemic, 2020-21.

Fluctuations in patient volume during the COVID-19 pandemic may have been particularly concerning for rural hospitals. We examined hospital discharge data from the Healthcare Cost and Utilization Project State Inpatient Databases to compare data from the COVID-19 pandemic period (March 8, 2020-December 31, 2021) with data from the prepandemic period (January 1, 2017-March 7, 2020). Changes in average daily medical volume at rural hospitals showed a dose-response relationship with community COVID-19 burden, ranging from a 13.2percent decrease in patient volume in periods of low transmission to a 16.5percent increase in volume in periods of high transmission. Overall, about 35percent of rural hospitals experienced fluctuations exceeding 20percent (in either direction) in average daily total volume, in contrast to only 13percent of urban hospitals experiencing similar magnitudes of changes. Rural hospitals with a large change in average daily volume were more likely to be smaller, government-owned, and critical access hospitals and to have significantly lower operating margins. Our findings suggest that rural hospitals may have been more vulnerable operationally and financially to volume shifts during the pandemic, which warrants attention because of the potential impact on these hospitals' long-term sustainability.