Surface Area Product Research Articles

Cerebrovascular Function in Sporadic and Genetic Cerebral Small Vessel Disease

ObjectiveCerebral small vessel diseases (SVDs) are associated with cerebrovascular dysfunction, such as increased blood–brain barrier leakage (permeability surface area product), vascular pulsatility, and decreased cerebrovascular reactivity (CVR). No studies assessed all 3 functions concurrently. We assessed 3 key vascular functions in sporadic and genetic SVD to determine associations with SVD severity, subtype, and interrelations.MethodsIn this prospective, cross‐sectional, multicenter INVESTIGATE‐SVDs study, we acquired brain magnetic resonance imaging in patients with sporadic SVD/cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), including structural, quantitative microstructural, permeability surface area product, blood plasma volume fraction, vascular pulsatility, and CVR (in response to CO2) scans. We determined vascular function and white matter hyperintensity (WMH) associations, using covariate‐adjusted linear regression; normal‐appearing white matter and WMH differences, interrelationships between vascular functions, using linear mixed models; and major sources of variance using principal component analyses.ResultsWe recruited 77 patients (45 sporadic/32 CADASIL) at 3 sites. In adjusted analyses, patients with worse WMH had lower CVR (B = −1.78, 95% CI −3.30, −0.27) and blood plasma volume fraction (B = −0.594, 95% CI −0.987, −0.202). CVR was worse in WMH than normal‐appearing white matter (eg, CVR: B = −0.048, 95% CI −0.079, −0.017). Adjusting for WMH severity, SVD subtype had minimal influence on vascular function (eg, CVR in CADASIL vs sporadic: B = 0.0169, 95% CI −0.0247, 0.0584). Different vascular function mechanisms were not generally interrelated (eg, permeability surface area product~CVR: B = −0.85, 95% CI −4.72, 3.02). Principal component analyses identified WMH volume/quantitative microstructural metrics explained most variance in CADASIL and arterial pulsatility in sporadic SVD, but similar main variance sources.InterpretationVascular function was worse with higher WMH, and in WMH than normal‐appearing white matter. Sporadic SVD‐CADASIL differences largely reflect disease severity. Limited vascular function interrelations may suggest disease stage‐specific differences. ANN NEUROL 2024

Understanding the Liver’s Role in the Clearance of Aβ40

The clearance of peripheral beta amyloid (Aβ) is a potential target for the treatment of Alzheimer’s disease (AD). The liver has been implicated in the elimination of Aβ from the peripheral circulation. Here, the single-pass uptake of Aβ40 in perfused livers from young and old rats (6 to 10 rats per group) was investigated with the multiple indicator dilution technique. Aβ40 had volumes of distribution between those of the vascular marker Evans Blue and the extracellular marker sucrose. The hepatic extraction of Aβ40 was negligible, explained in part by the small permeability surface area products consistent with a high endothelial barrier to liver uptake. There were no substantial effects of age on any of these results. In vitro experiments with isolated hepatocytes and liver sinusoidal endothelial cells showed only very small amounts of Aβ uptake consistent with low intrinsic clearance. These results indicate that the hepatic clearance of Aβ is capacity-limited, explained by the low-permeability surface area products and hepatocyte uptake. However, this does not preclude an effect of aging in longer-term in vivo studies where age-related changes in liver blood flow and protein binding influence liver clearance.

Insight into multi-ionic adsorption behavior of recycled cement paste exposed to chloride solutions

The multi-ionic adsorption behavior of recycled cement paste (RCP) exposed to NaCl and CaCl2 solutions is investigated in this study by comparing with that of the ordinary cement paste (OCP). The adsorption of Na+, K+, Ca2+, and Cl- in RCP and OCP are quantified by ICP-OES and potentiometric titration. RCP has larger adsorption capacity for Na+, K+, and Cl- compared to OCP, which is attributed to a lager specific surface area of RCP. For the multi-ion adsorption of OCP and RCP in both NaCl and CaCl2 solutions, the adsorption amount of minor cation ions are found to be influenced by the concentration of primary cation ion, reflecting a competitive adsorption among cation ions. Besides, the maximum Na+ adsorption amount is proportional to the product of the specific surface area and the percentage of the silanol groups in CSH measured by 29Si NMR spectroscopy. Additionally, molecular dynamics simulation is conducted to investigate the Na+ and Cl- adsorption behavior of CSH in OCP and RCP at a molecular level. The simulation results confirm the higher adsorption capacity of OCP than RCP.

Post-endovascular treatment, blood-brain barrier disruption, predicts patient outcomes better than pre-treatment status.

Blood-brain barrier (BBB) disruption is an important pathological change after cerebral infarction that exacerbates brain injury. We aimed to investigate and compare the predictive utility of pre-treatment BBB permeability (BBBP) and BBBP within 1 h after endovascular treatment (EVT) for hemorrhagic transformation (HT) and 90-day prognosis. Patients underwent preoperative computed tomography perfusion (CTP) and non-contrast CT (NCCT) within 1 h after EVT. Preoperative BBBP was determined by the relative permeability surface area product (rPS) in the hypoperfusion area. Postoperative BBBP was determined by the post-EVT Alberta Stroke Program Early CT Score (Post-ASPECTS), which is based on brain parenchymal hyperdensity on the postoperative NCCT. We included 100 patients. Univariate logistic regression analysis revealed correlations of preoperative rPS with HT, poor outcomes, and death. However, these correlations were not observed in multivariate logistic regression. A Post-ASPECTS ≤7 and could independently predict poor outcomes, while Post-ASPECTS ≤6 could independently predict death and HT. The baseline National Institutes of Health Stroke Scale (NIHSS) score could independently predict poor outcomes and death but not HT. A combined model using the baseline NIHSS and Post-ASPECTS scores had better predictive performance for poor outcomes and death than baseline NIHSS score alone; however, it was not superior to the predictive performance of the Post-ASPECTS score. The preoperative rPS cannot independently predict clinical outcomes in EVT-treated patients; contrastingly, the Post-ASPECTS score could independently predict poor outcomes, death, and HT. This parameter could inform prompt postoperative treatment decisions.

Electrospun photothermally active graphene-based nanofibers with a Retro-Diels-Alder reaction to initiate drug release

Externally controlled local drug release systems have garnered significant interest, with stimuli-responsive electrospun nanofibers emerging as a prominent platform for local drug delivery. Their advantages, such as a high surface area and facile production have made them appealing materials for various biomedical applications. While nanofiber scaffolds have been widely used for drug release through physical entrapment, control over the passive release and precise dosage regulation remains challenging. To overcome these limitations, in this study, maleimide-modified functional molecules were covalently conjugated to reduced graphene oxide-containing nanofiber scaffolds (average diameter 475 ± 94 nm) fabricated using furan-containing copolymers. The Diels-Alder cycloaddition at ambient temperature conjugates the molecules of interest, whereas the thermally promoted retro Diels-Alder cycloreversion reaction releases them. Photothermal heating using near-infrared light at 980 nm facilitated control over the drug release, and switching the irradiation on and off allows on-demand release. One can envision that these photothermally active nanofiber mats could enable on-demand drug delivery of a variety of active therapeutic agents for localized delivery.

Electrical driven pyrolysis reactor retrofit for indirect concentrated solar heat

Aiming for a climate-neutral economy, and the associated transition towards fuels produced from alternative feedstock, and to overcome some biomass pyrolysis unsuitable properties for the conventional combustion devices, plastics pyrolysis also produces oils, whose main compounds are also hydrocarbons, that can be used in conventional engines without so complex and costly upgrading processes.Most of the chemical reactions found in a pyrolysis process are endothermal thus, to fulfill that energy demand, the retrofit of a 4 kW electrical furnace pyrolysis reactor to indirect solar driven energy was assessed aiming to adapt it to a central receiver solar tower with up to 100kWth-peak, using air as heat transfer fluid.The heat demand along a typical pyrolysis test was experimentally assessed and a heat transfer mathematical model was defined to address the working constraints of the reactor. Additional analysis considering new design parameters were performed, namely sensitive analysis to the length of the new heating coil and its overall heat transfer coefficient, the reactor temperature set point, the inlet and outlet (to the atmosphere) gas temperature and working mass flow rates and temperatures were found to provide the same heat demand and minimize the waste heat.Considering both the heat source facility and the reactor constraints, it was found that the retrofit is possible providing that the product of surface area by the overall heat transfer coefficient (A·U) yields more than 17.7 W/K, for a reactor temperature set point of 450 °C and a maximum temperature inlet of 700 °C.

Coral geometry and why it matters.

Clonal organisms like reef building corals exhibit a wide variety of colony morphologies and geometric shapes which can have many physiological and ecological implications. Colony geometry can dictate the relationship between dimensions of volume, surface area, and length, and their associated growth parameters. For calcifying organisms, there is the added dimension of two distinct components of growth, biomass production and calcification. For reef building coral, basic geometric shapes can be used to model the inherent mathematical relationships between various growth parameters and how colony geometry determines which relationships are size-dependent or size-independent. Coral linear extension rates have traditionally been assumed to be size-independent. However, even with a constant calcification rate, extension rates can vary as a function of colony size by virtue of its geometry. Whether the ratio between mass and surface area remains constant or changes with colony size is the determining factor. For some geometric shapes, the coupling of biomass production (proportional to surface area productivity) and calcification (proportional to volume) can cause one aspect of growth to geometrically constrain the other. The nature of this relationship contributes to a species' life history strategy and has important ecological implications. At one extreme, thin diameter branching corals can maximize growth in surface area and resource acquisition potential, but this geometry requires high biomass production to cover the fast growth in surface area. At the other extreme, growth in large, hemispheroidal corals can be constrained by calcification. These corals grow surface area relatively slowly, thereby retaining a surplus capacity for biomass production which can be allocated towards other anabolic processes. For hemispheroidal corals, the rate of surface area growth rapidly decreases as colony size increases. This ontogenetic relationship underlies the success of microfragmentation used to accelerate restoration of coral cover. However, ontogenetic changes in surface area productivity only applies to certain coral geometries where surface area to volume ratios decrease with colony size.

The differential diagnosis of lung precursor glandular lesions, micro-invasive adenocarcinoma, and invasive adenocarcinoma using low dose spectral computed tomography perfusion imaging.

Few studies about the association between computed tomography (CT) perfusion imaging parameters and invasiveness in lung adenocarcinoma (LUAD) have been conducted using low dose spectral CT perfusion imaging. The purpose of this study was to investigate application of spectral revolution CT low-dose perfusion imaging in the differential diagnosis of different pathological subtypes of LUAD. This was a cross-sectional study based on historical data from January 2018 to May 2019 in Peking University Cancer Hospital & Institute. A total of 62 cases were enrolled, including 2 cases of atypical adenomatous hyperplasia (AAH), 3 cases of adenocarcinoma in situ (AIS), 4 cases of minimally invasive adenocarcinoma (MIA), and 53 cases of invasive adenocarcinoma (IAC), all confirmed with pathology. The inclusion and exclusion criteria were regulated. Using Revolution low-dose CT perfusion imaging (GE, USA), the CT perfusion parameters of hemodynamics were obtained: blood flow (BF), blood volume (BV), impulse residue function time of arrival (IRF TO), maximum slope of increase (MSI), mean transit time (MTT), permeability surface area product (PS), positive enhancement integral (PEI), and maximum enhancement time (Tmax). Univariate analysis of variance (ANOVA) or Kruskal-Wallis test was used to compare the differences of CT perfusion quantitative parameters among AAH, AIS, MIA, and IAC. Mann-Whitney test was used to compare the difference of CT perfusion imaging parameters between preinvasive lesions (AAH and AIS) and invasive lung cancer (MIA and IAC). Statistically significant differences in IRF TO were observed in LUAD with different invasiveness, namely, among AIS, MIA, and IAC groups (0.56±0.74 vs. 0.54±1.08 vs. 4.39±2.19, P=0.004). Statistically significant differences in IRF TO were also observed between pre-invasive lesions group (AAH and AIS) and invasive lung cancer group (MIA and IAC) (1.12±1.27 vs. 3.75±2.79, P=0.031), and between AAH + AIS + MIA groups and IAC group (0.83±1.13 vs. 4.12±2.69, P<0.001). There were no statistically significant differences in other CT perfusion parameters of hemodynamics among different pathological subtypes of LUAD (P>0.05). The low-dose perfusion parameter IRF TO of revolution CT has the potential to be employed in the differential diagnosis of different pathological subtypes of LUAD.

HKUST-1 MOF nanoparticles: a non-classical crystallization route in supercritical CO2.

Reducing MOF particles to the nanoscale size range is beneficial due to their increased surface-to-volume ratio, higher defects exposing metals and ligands, and short diffusion path. While great efforts have been made to reduce the particle sizes by controlling the reaction kinetics or terminating the particle growth, large-scale, rapid synthesis of MOF nanoparticles (NPs) remains a challenge. Here, we report supercritical (sc) CO2-assisted synthesis of HKUST-1 NPs in a continuous flow reactor, which yielded pure and thermally stable MOFs with median sizes of 110-250 nm and BET surface areas of 1610-1890 m2 g-1 under 10 seconds synthesis time. ScCO2 and ethanol with a molar ratio of 9 : 1 are used as co-solvents for the fast nucleation of HKUST-1 and crystal formation. A typical dry yield of 53.7 wt% is achieved with 0.1 M Cu precursor under mild conditions at 75 °C and 13 MPa. The space-time yields and surface area production rates are 5668 kg m-3 d-1 and 1.0 × 1010 m2 m-3 d-1. Particle size and morphology analyses indicate that aggregation of nascent structures occurs in the aerosolized state, leading to a non-classical crystal growth mechanism and enabling multiple pathways for tuning the synthesis process. With the ability to recycle CO2, solvents, and unreacted precursors, the method can be used for the scalable production of MOFs.

(Invited) The Effect of Surfactants on Vanadium Electrochemistry in Porous Carbon Electrodes

We present a study of vanadium electrochemistry in porous electrodes with and without sodium dodecyl sulfate (SDS) additives present. Carbon paper and felt electrodes are compared. Carbon felt electrodes are the de facto standard in flow batteries. There are significant differences in the electronic conductivity of these media. The carbon paper has a much higher conductivity than the felt, which has an electronic conductivity similar to the ionic conductivity of the electrolytes used. The latter fact motivates an extension of available theory for polarization curve fitting to explicitly include both electronic and ionic contributions in the porous electrode. We demonstrate agreement between our model and an existing model evaluated at the limit where electrode conductivity is significantly greater than electrolyte conductivity. Our model uses the product of the electrode surface area per volume ratio and the heterogeneous electron transfer rate constant, and the Damköhler number as fitting parameters for carbon paper and felt electrodes. We discuss the effect of SDS additives on kinetics in the context of the cation hydration shell for the vanadium ions. To this point, we apply Marcus-Hush-Chidsey formalism to our porous electrode model to quantify reorganization energies obtained through polarization curve fitting. This work was supported as part of the Breakthrough Electrolytes for Energy Storage (BEES2), an Energy Frontier Research Center funded by the United States. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0019409.

Preparation of thermal energy storage microcapsule with double-layer ceramic shell possessing sponge effect to improve the thermal cycling performance

In present study, thermal energy storage microcapsules with double-layer ceramic shell were fabricated and thermal cycling test was conducted. Thermal cycling test results showed that when ceramic shell constituted of dense inner layer and loose outer layer, the microcapsule had excellent thermal stability. After 3000 thermal cycles, latent heat retention ratio of the microcapsule was more than 90 % and almost no leakage of molten core. This super durability and stability attributed to “sponge effect” of loose outer layer which offered volume buffer for microcapsule core and inhibited molten core overflow during phase change. According to the Mass Conservation Law, criterion Г for describing “sponge effect” was deduced. Г was defined as a quarter of the product of the specific surface area of the microcapsule and criterion Г was derived as Г≥1ρL−1ρS. The criterion shows that when the value of Г is larger than or equal to the difference between the specific volumes of liquid and solid phase change material, microcapsule core is not overflow during phase change. Criterion Г provides theoretical guidance for the preparation of thermal energy storage microcapsules with excellent thermal cycling performance.

Blood-brain barrier breakdown in COVID-19 ICU survivors: an MRI pilot study.

Coronavirus disease 2019 (COVID-19) results in severe inflammation at the acute stage. Chronic neuroinflammation and abnormal immunological response have been suggested to be the contributors to neuro-long-COVID, but direct evidence has been scarce. This study aims to determine the integrity of the blood-brain barrier (BBB) in COVID-19 intensive care unit (ICU) survivors using a novel MRI technique. COVID-19 ICU survivors (n=7) and age and sex-matched control participants (n=17) were recruited from June 2021 to March 2023. None of the control participants were hospitalized due to COVID-19 infection. The COVID-19 ICU survivors were studied at 98.6 ± 14.9 days after their discharge from ICU. A non-invasive MRI technique was used to assess the BBB permeability to water molecules, in terms of permeability surface area-product (PS) in the units of mL/100 g/min. PS was significantly higher in COVID-19 ICU survivors (p=0.038) when compared to the controls, with values of 153.1 ± 20.9 mL/100 g/min and 132.5 ± 20.7 mL/100 g/min, respectively. In contrast, there were no significant differences in whole-brain cerebral blood flow (p=0.649) or brain volume (p=0.471) between the groups. There is preliminary evidence of a chronic BBB breakdown in COVID-19 survivors who had a severe acute infection, suggesting a plausible contributor to neurological long-COVID symptoms.

Role of Permeability Surface Area Product in Grading of Brain Gliomas using CT Perfusion.

Purpose The aim of this study was to evaluate the role of permeability surface area product in grading brain gliomas using computed tomography (CT) perfusion Materials and Methods CT perfusion was performed on 33 patients with brain glioma diagnosed on magnetic resonance imaging. Of these, 19 had high-grade glioma and 14 had low-grade glioma on histopathological follow-up. CT perfusion values were obtained and first compared between the tumor region and normal brain parenchyma. Then the relative values of perfusion parameters were compared between high- and low-grade gliomas. Cut-off values, sensitivity, specificity, and strength of agreement for each parameter were calculated and compared subsequently. A conjoint factor (permeability surface area product + cerebral blood volume) was also evaluated since permeability surface area product and cerebral blood volume are considered complimentary factors for tumor vascularity. Results All five perfusion parameters namely permeability surface area product, cerebral blood volume, cerebral blood flow, mean transit time, and time to peak were found significantly higher in the tumor region than normal brain parenchyma. Among these perfusion parameters, only relative permeability surface area product and relative cerebral blood volume were found significant in differentiating high- and low-grade glioma. Moreover, relative permeability surface area product was significantly better than all other perfusion parameters with highest sensitivity and specificity (97.74 and 100%, respectively, at a cut-off of 9.0065). Relative permeability surface area product had a very good agreement with the histopathology grade. The conjoint factor did not yield any significant diagnostic advantage over permeability surface area product. Conclusion Relative permeability surface area product and relative cerebral blood volume were helpful in differentiating high- and low-grade glioma; however, relative permeability surface area product was significantly better than all other perfusion parameters. Grading brain gliomas using relative permeability surface area product can add crucial value in their management and prognostication; hence, it should be evaluated in the routine CT perfusion imaging protocol.

A Calcination-Free Sol-Gel Method to Prepare TiO2 -Based Hybrid Semiconductors for Enhanced Visible Light-Driven Hydrogen Production.

Invited for this month's cover are the collaborating groups of Dr. Jianwei Li at the University of Turku and Prof. Chunman Jia, Kang Yang and Dan Wei at Hainan University. The cover image compares the structure of calcined (left) and non-calcined (right) rutile TiO2 doped with a molecule NA. The calcination process enlarges the pores in TiO2 , reducing its surface area and hydrogen production efficiency under visible light. The "sad face" symbolizes the damaged pore structure. Conversely, doping TiO2 with NA without high-temperature calcination forms a covalent bond, resulting in smaller pores, larger surface area, and improved hydrogen production efficiency. The "smiley face" represents the structurally intact TiO2 hybrid material. More information can be found in the Research Article by Jianwei Li, Chunman Jia, and co-workers.

Features of productivity formation of different maturity terms perennial cereal grasses between mowings depending on the fertilizing system

Purpose. To establish productivity indicators and terms of mowing perennial grasses of different maturity terms depending on fertilizer, Methods. Field, laboratory, mathematical and statistical. Results. The research results of productivity indicators of different maturity terms perennial grasses depending on the fertilization system between the mowings and the peculiarities of the growth of dry biomass during formation of the first mowing on the sod-podzolic soil of the Carpathian region, conducted during 2011-2013, are presented. Conclusions. Productivity of various types of perennial grasses on nitrogen-free backgrounds in the 1st mowing varied between 1.22-1.67 t/ha of dry mass, in the 2nd – 1.06-1.40, and in the 3rd – in in the range of 0.79-1.01 t/ha of dry mass. The most productive in the 1st mowing were Bromus inermis and Phleum pretense L., in the 2nd – Dactylis glomerata, Festuca orientals (Hack.), and Lolium perenne. The most uniform distribution of the dry mass yield in the mowings with the smallest coefficient of variation (6-12%) was characteristic of the Dactylis glomerata, and the least uniform with the largest coefficient (29-35%) – of the Phleum pretense L. Nitrogen had the greatest effect on the productivity of cereal grass stands. With the application of P60K60, productivity increased by 3-23% compared to the variant without fertilizers, and with the application of N90P60K60 – by 1.8-1.9 times. The highest indicators of daily increase in dry mass (75-206 kg/ha), leaf surface area (30.3-43.1 thousand m2/ha) and net productivity of photosynthesis (1.16-4.78 g/m2 per day) in the 1st mowing fell on the period of tuberization-the beginning of the earing of cereal grasses. The growth of productivity of dry biomass, leaf surface area and net productivity of photosynthesis occurs before the flowering phase of grasses.

HSD12 Measuring Psoriasis Disease Activity in the Real-World Setting: Relationship between the Physician Global Assessment and Body Surface Area Product and the Psoriasis Area and Severity Index

Severity of psoriasis is a major factor in a physician’s treatment decision. The objective of this research was to evaluate the relationship between the Physician Global Assessment and Body Surface Area product (PGA x BSA) and the Psoriasis Area and Severity Index (PASI) for assessing disease activity in psoriasis patients in specialty dermatology networks in the United States (US).

Photosynthetic productivity of sorghum (Sorghum bicolor L. (Moenh) in the conditions of the Right-Bank Forest-Steppe of Ukraine

Sorghum (Sorghum bicolor L. (Moenh) is a technical, food, and fodder crop and can be used for various purposes, given its value, the acreage should be substantially expanded in Ukraine, and the elements of cultivation technology should be thoroughly examined. The purpose of the study was to determine the effect of the growth regulator on the photosynthetic productivity of sorghum in the conditions of the Right-Bank Forest-Steppe of Ukraine. The following methods were used in the study: field, measuring and weighing, mathematical, and statistical. The study was conducted in conditions of unstable moisture in the Right-Bank Forest-Steppe of Ukraine in 2016-2019. Based on the results of the study, it was determined that the use of a plant growth regulator affected photosynthetic productivity, namely, the leaf surface area, photosynthetic potential and net photosynthesis productivity. The indicators for the content of chlorophylls changed. Thus, the assimilation area of leaves reached a maximum with seed treatment and spraying of crops and amounted to 8.56 thousand m2 /ha during the tillering period, during the period of stem elongation – 29.6 thousand m2 /ha, during flowering and full ripeness – 40.32 and 4.97 thousand m2 /ha. Net photosynthetic productivity in the control was the lowest – 4.67 g/m2 , the use of a growth regulator on seeds and crops contributed to its increase by 0.27 and 0.79 g/m2 . With the treatment of seeds and crops, the net photosynthetic productivity was the highest and amounted to 6.12 g/m2 . The sum of chlorophylls a+b had the highest rates during the tasselling period and, depending on the experiment options, ranged from 4.36 to 5.35. The yield of grain and biomass also varied depending on the use of the preparation, and was the highest in the version with seed treatment and spraying of crops (7.1 and 35.9 t/ha). The close relationship between photosynthetic productivity and the yield of sorghum is also determined. The study can contribute to the widespread use of growth regulators in sorghum crops, ensure the full development of plants, and increase grain yields and biomass

Blood-brain barrier leakage hotspots collocating with brain lesions due to sporadic and monogenic small vessel disease.

Blood-brain barrier (BBB) is known to be impaired in cerebral small vessel disease (SVD), and is measurable by dynamic-contrast enhancement (DCE)-MRI. In a cohort of 69 patients (42 sporadic, 27 monogenic SVD), who underwent 3T MRI, including DCE and cerebrovascular reactivity (CVR) sequences, we assessed the relationship of BBB-leakage hotspots to SVD lesions (lacunes, white matter hyperintensities (WMH), and microbleeds). We defined as hotspots the regions with permeability surface area product highest decile on DCE-derived maps within the white matter. We assessed factors associated with the presence and number of hotspots corresponding to SVD lesions in multivariable regression models adjusted for age, WMH volume, number of lacunes, and SVD type. We identified hotspots at lacune edges in 29/46 (63%) patients with lacunes, within WMH in 26/60 (43%) and at the WMH edges in 34/60 (57%) patients with WMH, and microbleed edges in 4/11 (36%) patients with microbleeds. In adjusted analysis, lower WMH-CVR was associated with presence and number of hotspots at lacune edges, and higher WMH volume with hotspots within WMH and at WMH edges, independently of the SVD type. In conclusion, SVD lesions frequently collocate with high BBB-leakage in patients with sporadic and monogenic forms of SVD.

Physiological Response of Stored Pomegranate Fruit Affected by Simulated Impact

Mechanical damage resulting from excessive impact force during handling and other postharvest operations from harvesting to consumption is a critical quality problem in fresh produce marketing. The study investigates the impact of bruise damage, storage temperature, and storage period on the physiological responses of Omani pomegranate fruit cultivar 'Helow'. Fruits were subjected to low (45°; 1.18 J) and high (65°; 2.29 J) impact levels using a pendulum test by hitting the fruit on the cheek side. Bruised and non-bruised fruit were stored at 5 and 22 °C for 28 days. Bruise measurements, water loss per unit mass, water loss per surface area, firmness, fruit size measurements, geometric mean diameter, surface area, fruit volume, color parameters, respiration rate, and ethylene production rate were evaluated. Bruise area, bruise volume, and bruise susceptibility of damaged pomegranate fruit were increased as impact level, storage duration, and storage temperature increased. Pomegranates damaged at a high impact level and conditioned at 22 °C showed 20.39% weight loss on the last day of storage compared to the control and low-impact-bruised fruit. Firmness and geometric mean diameter were significantly (p < 0.05) reduced by bruising at a high impact level. Impact bruising level and storage temperature decreased lightness, yellowness, browning index, and increased redness over time. Furthermore, the respiration rate was five times higher in the non-bruised and low- and high-impact-injured fruit stored at 22 °C than that stored at 5 °C. The ethylene production rate recorded its highest value on day 21 in high-level-impact-bruised pomegranate fruit. The bruise susceptibility was strongly correlated with the majority of the studied parameters. This study can confirm that bruising can affect not only the visual quality characteristics but also the physiological attributes of pomegranate fruit; therefore, much care is required to preserve fresh produce and avoid any mechanical damage and losses during postharvest handling.

Spatiotemporal Analysis of Urban Expansion in the Mountainous Hindu Kush Himalayas Region

As a major human activity, urbanization exerts a strong impact on the fragile ecosystem in the Hindu Kush Himalayas (HKH) region. To maintain sustainable development, reliable data on urban land change are required to assess the impact of urbanization. Here, the reliability evaluation of four global fine-resolution impervious surface area (ISA) products: global annual impervious area (GAIA), global annual urban dynamics (GAUD), global impervious surface area (GISA), and global urban expansion (GUE) was carried out. The characteristics of urban expansion for five representative cities including Kabul, Lhasa, Lijiang, Thimphu, and Xining were remarkably different. Based on the results of incremental analysis and the spatial difference of the ISA, it was found that the GAIA dataset at a 30-m spatial resolution could provide better ISA information than the others in characterizing urban expansion in the mountainous region. Subsequently, the changes in the urban area were analyzed using the GAIA dataset from 1993 to 2018. In general, human settlements had grown, with the transformation of small villages into larger towns and some towns into major cities. Urban expansion would continuously intensify the contradictions between human activity and sustainability and exert a more significant impact on the fragile ecosystem in the HKH region. More attention should be paid to the impact of urbanization on the fragile mountainous ecosystem.