Nevin Manimala

Proc Natl Acad Sci U S A. 2023 May 23;120(21):e2216765120. doi: 10.1073/pnas.2216765120. Epub 2023 May 15.

ABSTRACT

Urbanization extensively modifies surface roughness and properties, impacting regional climate and hydrological cycles. Urban effects on temperature and precipitation have drawn considerable attention. These associated physical processes are also closely linked to clouds’ formation and dynamics. Cloud is one of the critical components in regulating urban hydrometeorological cycles but remains less understood in urban-atmospheric systems. We analyzed satellite-derived cloud patterns spanning two decades over 447 US cities and quantified the urban-influenced cloud patterns diurnally and seasonally. The systematic assessment suggests that most cities experience enhanced daytime cloud cover in both summer and winter; nocturnal cloud enhancement prevails in summer by 5.8%, while there is modest cloud suppression in winter nights. Statistically linking the cloud patterns with city properties, geographic locations, and climate backgrounds, we found that larger city size and stronger surface heating are primarily responsible for summer local cloud enhancement diurnally. Moisture and energy background control the urban cloud cover anomalies seasonally. Under strong mesoscale circulations induced by terrains and land-water contrasts, urban clouds exhibit considerable nighttime enhancement during warm seasons, which is relevant to strong urban surface heating interacting with these circulations, but other local and climate impacts remain complicated and inconclusive. Our research unveils extensive urban influences on local cloud patterns, but the effects are diverse depending on time, location, and city properties. The comprehensive observational study on urban-cloud interactions calls for more in-depth research on urban cloud life cycles and their radiative and hydrologic implications under the urban warming context.

PMID:37186862 | DOI:10.1073/pnas.2216765120

Proc Natl Acad Sci U S A. 2023 May 23;120(21):e2213836120. doi: 10.1073/pnas.2213836120. Epub 2023 May 15.

ABSTRACT

In recent years, cellular biomechanical properties have been investigated as an alternative to morphological assessments for oocyte selection in reproductive science. Despite the high relevance of cell viscoelasticity characterization, the reconstruction of spatially distributed viscoelastic parameter images in such materials remains a major challenge. Here, a framework for mapping viscoelasticity at the subcellular scale is proposed and applied to live mouse oocytes. The strategy relies on the principles of optical microelastography for imaging in combination with the overlapping subzone nonlinear inversion technique for complex-valued shear modulus reconstruction. The three-dimensional nature of the viscoelasticity equations was accommodated by applying an oocyte geometry-based 3D mechanical motion model to the measured wave field. Five domains-nucleolus, nucleus, cytoplasm, perivitelline space, and zona pellucida-could be visually differentiated in both oocyte storage and loss modulus maps, and statistically significant differences were observed between most of these domains in either property reconstruction. The method proposed herein presents excellent potential for biomechanical-based monitoring of oocyte health and complex transformations across lifespan. It also shows appreciable latitude for generalization to cells of arbitrary shape using conventional microscopy equipment.

PMID:37186851 | DOI:10.1073/pnas.2213836120

Proc Natl Acad Sci U S A. 2023 May 23;120(21):e2301707120. doi: 10.1073/pnas.2301707120. Epub 2023 May 15.

ABSTRACT

[C. Koch, S. Ullman, Hum. Neurobiol.4, 219-227 (1985)] proposed a 2D topographical salience map that took feature-map outputs as its input and represented the importance “saliency” of the feature inputs at each location as a real number. The computation on the map, “winner-take-all,” was used to predict action priority. We propose that the same or a similar map is used to compute centroid judgments, the center of a cloud of diverse items. [P. Sun, V. Chu, G. Sperling, Atten. Percept. Psychophys.83, 934-955 (2021)] demonstrated that following a 250-msec exposure of a 24-dot array of 3 intermixed colors, subjects could accurately report the centroid of each dot color, thereby indicating that these subjects had at least three salience maps. Here, we use a postcue, partial-report paradigm to determine how many more salience maps subjects might have. In 11 experiments, subjects viewed 0.3-s flashes of 28 to 32 item arrays composed of M, M = 3,…,8, different features followed by a cue to mouse-click the centroid of items of just the post-cued feature. Ideal detector response analyses show that subjects utilized at least 12 to 17 stimulus items. By determining whether a subject’s performance in (M-1)-feature experiments could/could-not predict performance in M-feature experiments, we conclude that one subject has at least 7 and the other two have at least five salience maps. A computational model shows that the primary performance-limiting factors are channel capacity for representing so many concurrently presented groups of items and working-memory capacity for so many computed centroids.

PMID:37186842 | DOI:10.1073/pnas.2301707120

Proc Natl Acad Sci U S A. 2023 May 23;120(21):e2216234120. doi: 10.1073/pnas.2216234120. Epub 2023 May 15.

ABSTRACT

Neurodegenerative diseases, such as Alzheimer’s disease (AD), are associated with protein misfolding and aggregation into amyloid fibrils. Increasing evidence suggests that soluble, low-molecular-weight aggregates play a key role in disease-associated toxicity. Within this population of aggregates, closed-loop pore-like structures have been observed for a variety of amyloid systems, and their presence in brain tissues is associated with high levels of neuropathology. However, their mechanism of formation and relationship with mature fibrils have largely remained challenging to elucidate. Here, we use atomic force microscopy and statistical theory of biopolymers to characterize amyloid ring structures derived from the brains of AD patients. We analyze the bending fluctuations of protofibrils and show that the process of loop formation is governed by the mechanical properties of their chains. We conclude that ex vivo protofibril chains possess greater flexibility than that imparted by hydrogen-bonded networks characteristic of mature amyloid fibrils, such that they are able to form end-to-end connections. These results explain the diversity in the structures formed from protein aggregation and shed light on the links between early forms of flexible ring-forming aggregates and their role in disease.

PMID:37186840 | DOI:10.1073/pnas.2216234120

Technol Cancer Res Treat. 2023 Jan-Dec;22:15330338231170495. doi: 10.1177/15330338231170495.

ABSTRACT

BACKGROUND: The incorporation of noncoplanar beam arrangements has been proposed in liver radiotherapy modalities, which can reduce the dose in normal tissues compared to coplanar techniques. Noncoplanar radiotherapy techniques for hepatocellular carcinoma treatment based on the Linac design have a limited effective arc angle to avoid collisions.

PURPOSE: To propose a novel noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system and investigate its performance in hepatocellular carcinoma patients.

METHODS: The computed tomography was deflected 90° to meet the structure of a cage-like radiotherapy system and design the noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan in the Pinnacle3 planning system. An noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan was customized for each of 10 included hepatocellular carcinoma patients, with 6 dual arcs ranging from -30° to 30°. Six couch angles were set with an interval of 36° and distributed along with the longest diameter of planning target volume. The dosimetric parameters of noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system plan were compared with the noncoplanar volumetric modulated arc therapy and volumetric modulated arc therapy plan.

RESULTS: The 3 radiotherapy techniques regarding planning target volume were statistically different for D98%, D2%, conformity index, and homogeneity index with χ² = 9.692, 14.600, 8.600, and 12.600, and P = .008, .001, .014, and .002, respectively. Further multiple comparisons revealed that noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system significantly reduced the mean dose (P = .005) and V5 (P = .005) of the normal liver, the mean dose (P = .005) of the stomach, and V30 (P = .028) of the lung compared to noncoplanar volumetric modulated arc therapy. Noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system significantly reduced the mean dose (P = .005) and V5 (P = .005) of the normal liver, the mean dose (P = .017) of the spinal cord, V50 (P = .043) of the duodenum, the maximum dose (P = .007) of the esophagus, and V30 (P = .047) of the whole lung compared to volumetric modulated arc therapy. The results indicate that noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system protects the normal liver, stomach, and lung better than noncoplanar volumetric modulated arc therapy and protects the normal liver, spinal cord, duodenum, esophagus, and lung better than volumetric modulated arc therapy.

CONCLUSIONS: The noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system technique with the arrangement of noncoplanar arcs provided optimal dosimetric gains compared with noncoplanar volumetric modulated arc therapy and volumetric modulated arc therapy, except for the heart. Noncoplanar volumetric modulated arc therapy technique based on a cage-like radiotherapy system should be considered in more clinically challenging cases.

PMID:37186800 | DOI:10.1177/15330338231170495

Can J Occup Ther. 2023 Jun;90(2):161-172. doi: 10.1177/00084174231160954.

ABSTRACT

Background. Physical activity (PA) is essential for maintaining well-being in adults with disabilities. This population experienced reduced PA during the COVID-19 pandemic; yet, the impact on quality of PA participation remains unclear. Purpose. This secondary analysis explored how pandemic restrictions impacted six experiential dimensions of quality of PA participation among adults with disabilities. Methods. An exploratory sequential mixed-methods design, including semi-structured interviews (n = 10) and self-reported surveys (n = 61), was conducted in May-2020 and February-2021. Quality of PA participation was measured using the Measure of Experiential Aspects of Participation (MeEAP). Participants included community-dwelling adults over 19 years of age (mean 59.2 ± 14.0 years) living with stroke, spinal cord injury, or other physical disabilities. Findings. Directed content analysis identified three themes related to adjusting PA participation for restrictions, motivation barriers, and valuing social support. These themes highlighted five factors, such as resilience, as potential quantitative predictors of quality of PA participation. While paired correlations with MeEAP scores were observed, these factors were not statistically predictive in multiple regression analysis (adjusted R² = -0.14, F(10,50) = 0.92, p = .53). Implications. The interplay between Meaning, Autonomy, Engagement, and Belongingness dimensions of quality of PA participation was complex, with an emphasized role for mental health, in adults with disabilities.

PMID:37186790 | DOI:10.1177/00084174231160954

Clin Rehabil. 2023 May 15:2692155231172009. doi: 10.1177/02692155231172009. Online ahead of print.

ABSTRACT

OBJECTIVE: To examine the proportion of people with aphasia (PwA) included and retained in randomised controlled trials (RCTs) of stroke interventions published in the previous 6 years, as well as aphasia-relevant eligibility criteria and inclusion/retention strategies.

DATA SOURCES: Comprehensive searching of Embase, PubMed and Medline (Ovid) for the period January 2016 – November 2022.

REVIEW METHODS: RCTs examining stroke interventions targeting cognition, psychological wellbeing/health-related quality of life (HRQL), multidisciplinary rehabilitation, and self-management were included. Methodological quality was assessed using the Critical Appraisal Skills Programme (CASP) Randomised Controlled Trial checklist. Descriptive statistics were applied to extracted data, and results were reported narratively.

RESULTS: Fifty-seven RCTs were included. These examined self-management (32%), physical (26%) psychological wellbeing/HRQL (18%), cognitive (14%), and multidisciplinary (11%) interventions. Of 7313 participants, 107 (1.5%) had aphasia and were included in three trials. About one-third did not report on aphasia (32%); over one quarter required functional communication (28%); one quarter excluded all aphasia (25%); and 14% excluded severe aphasia. No aphasia-specific inclusion/retention strategies were available.

CONCLUSION: The findings highlight ongoing under-representation. However, due to shortcomings in aphasia reporting, the findings may underestimate actual inclusion rate. Excluding PwA has implications for the external validity, effectiveness, and implementation of stroke research findings. Triallists may require support in aphasia research strategies and methodological reporting.

PMID:37186769 | DOI:10.1177/02692155231172009

Clin Appl Thromb Hemost. 2023 Jan-Dec;29:10760296231174001. doi: 10.1177/10760296231174001.

ABSTRACT

In patients with liver failure complicated by acute kidney injury, renal replacement therapy (RRT) is often required to improve the internal environment. The use of anticoagulants for RRT in patients with liver failure remains controversial. We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for studies. The methodological quality of the included studies was assessed using the Methodological Index for Nonrandomized Studies. A meta-analysis was performed using R software (version 3.5.1) and Review Manager (version 5.3.5). During RRT, 348 patients from 9 studies received regional citrate anticoagulation (RCA), and 127 patients from 5 studies received heparin anticoagulation (including heparin and LMWH). Among patients who received RCA, the incidence of citrate accumulation, metabolic acidosis, and metabolic alkalosis were 5.3% (95% confidence interval [CI]: 0%-25.3%), 26.4% (95% CI: 0-76.9), and 1.8% (95% CI: 0-6.8), respectively. The potassium, phosphorus, total bilirubin (TBIL), and creatinine levels were lower, whereas the serum pH, bicarbonate, base excess levels, and total calcium/ionized calcium ratio were higher after treatment than before treatment. Among patients who received heparin anticoagulation, the TBIL levels were lower, whereas the activated partial thromboplastin clotting time and D-dimer levels were higher after treatment than before treatment. The mortality rates in the RCA and heparin anticoagulation groups were 58.9% (95% CI: 39.2-77.3) and 47.4% (95% CI: 31.1-63.7), respectively. No statistical difference in mortality was observed between the 2 groups. For patients with liver failure, the administration of RCA or heparin for anticoagulation during RRT under strict monitoring may be safe and effective.

PMID:37186766 | DOI:10.1177/10760296231174001

Opt Lett. 2023 May 15;48(10):2595-2598. doi: 10.1364/OL.488924.

ABSTRACT

A novel lateral scanning Raman scattering lidar (LSRSL) system is proposed, aiming to realize the accurate measurement of atmospheric temperature and water vapor from the ground to a height of interest and to overcome the effect of a geometrical overlap function of backward Raman scattering lidar. A configuration of the bistatic lidar is employed in the design of the LSRSL system, in which four horizontally aligned telescopes mounted on a steerable frame to construct the lateral receiving system are spatially separated to look at a vertical laser beam at a certain distance. Each telescope, combined with a narrowband interference filter, is utilized to detect the lateral scattering signals of the low- and high-quantum-number transitions of the pure rotational Raman scattering spectra and vibrational Raman scattering spectra of N₂ and H₂O. The profiling of lidar returns in the LSRSL system is performed by the elevation angle scanning of the lateral receiving system, in which the intensities of the lateral Raman scattering signals at each setting of elevation angles are sampled and analyzed. Preliminary experiments are carried out after the construction of a LSRSL system in Xi’an city, whose retrieval results and statistical error analyses present a good performance in the detection of atmospheric temperature and water vapor from the ground to a height of 1.11 km and show the feasibility for combination with backward Raman scattering lidar in atmospheric measurement.

PMID:37186717 | DOI:10.1364/OL.488924

J Clin Endocrinol Metab. 2023 May 15:dgad261. doi: 10.1210/clinem/dgad261. Online ahead of print.

ABSTRACT

CONTEXT: Hypothyroidism is a common yet under-recognized condition in chronic kidney disease (CKD) patients, which may lead to end-organ complications if left untreated.

OBJECTIVE: We developed a prediction tool to identify CKD patients at-risk for incident hypothyroidism.

METHODS: Among 15,642 patients with stages 4-5 CKD without evidence of pre-existing thyroid disease, we developed and validated a risk prediction tool for the development of incident hypothyroidism (defined as TSH > 5.0mIU/L) using the Optum Labs Data Warehouse, which contains de-identified administrative claims, including medical and pharmacy claims and enrollment records for commercial and Medicare Advantage enrollees as well as electronic health record data. Patients were divided into a two-thirds development set and a one-third validation set. Prediction models were developed using Cox models to estimate probability of incident hypothyroidism.

RESULTS: There were 1650 (11%) cases of incident hypothyroidism during a median follow-up of 3.4 years. Characteristics associated with hypothyroidism included: older age, White race, higher BMI, low serum albumin, higher baseline TSH, hypertension, congestive heart failure, exposure to iodinated contrast via angiogram or CT scan, and amiodarone use. Model discrimination was good with similar C-statistics in the development and validation datasets: 0.77 (95%CI) 0.75-0.78 and 0.76 (95%CI) 0.74-0.78, respectively. Model goodness-of-fit (GOF) tests showed adequate fit in the overall cohort (p = 0.47) as well as in a subcohort of stage 5 CKD patients (p = 0.33).

CONCLUSION: In a national cohort of CKD patients, we developed a clinical prediction tool identifying those at-risk for incident hypothyroidism to inform prioritized screening, monitoring, and treatment in this population.

PMID:37186674 | DOI:10.1210/clinem/dgad261