bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal Performance of Micro-Jet Impingement Device With Parallel Flow, Jet-Adjacent Fluid Removal
Authors: Bandhauer Todd M. , Hobby David R. , Jacobsen Chris , Sherrer Dave 
Published: August 2018

In a variety of electronic systems, cooling of various components imposes a significant challenge. A major aspect that inhibits the performance of many cooling solutions is the thermal resistance between the chip package and the cooling structure. Due to its low thermal conductivity, the thermal interface material (TIM) layer imposes a significant thermal resistance on the chip to cooling fluid thermal path. Advanced cooling methods that bypass the TIM have shown great potential in research and some specialty applications, yet have not been adopted widely by industry due to challenges associated with practical implementation and economic constraints. One advanced cooling method that can bypass the TIM is jet impingement. The impingement cooling device investigated in the current study is external to the integrated circuit (IC) package and could be easily retrofitted onto any existing microchip, similar to a standard heatsink. Jet impingement cooling has proven effective in previous studies. However, it has been shown that jet-to-jet interference severely degrades thermal performance of an impinging jet array. The present research addresses this challenge by utilizing a flow path geometry that allows for withdrawal of the impinging fluid immediately adjacent to each jet in the array.
In this study, a jet impingement cooling solution for high-performance ICs was developed and tested. The cooling device was fabricated using modern advanced manufacturing techniques and consisted of an array of micro-scale impinging jets. A second array of fluid return paths was overlain across the jet array to allow for direct fluid extraction in the immediate vicinity of each jet, and fluid return passages were oriented in parallel to the impinging jets. The following key geometric parameters were utilized in the device: jet diameter (D = 300μm), distance from jet to impinging surface (H/D = 2.5), spacing between jets (S/D = 8), spacing between fluid returns (Sr/D = 8), diameter of fluid returns (Dr/D = 5). The device was mounted to a 2cm × 2cm uniformly heated surface which produced up to 165W and the resulting fluid-to-surface temperature difference was measured at a variety of flow rates. For this study, the device was tested using single-phase water. Jet Reynolds number ranged from 300–1500 and an average heat transfer coefficient of 13,100 W m−2 K−1 was achieved at a Reynolds number of only Red = 305.
Numerical Investigation of Heat Transfer in the Wake of a Single Highly Confined Bubble in a Horizontal Minichannel
Authors: Willard John R. , Hollingsworth D. Keith 
Published: August 2018

Confined bubbly flows in millimeter-scale channels produce significant heat transfer enhancement when compared to single-phase flows. Experimental studies support the hypothesis that the enhancement is driven by a convective phenomenon in the liquid phase as opposed to sourcing from microlayer evaporation or active nucleation. A numerical investigation of flow structure and heat transfer produced by a single bubble moving through a millimeter-scale channel was performed in order to document the details of this convective mechanism. The simulation includes thermal boundary conditions emulating those of the experiments, and phase change was omitted in order to focus only on the convective mechanism. The channel is horizontal with a uniform-heat-generation upper wall and an adiabatic lower surface. A Lagrangian framework was adopted such that the computational domain surrounds the bubble and moves at the nominal bubble speed. The liquid around the bubble moves as a low-Reynolds-number unsteady laminar flow. The volume-of-fluid method was used to track the liquid/gas interface.
This paper reviews the central results of this simulation regarding wake heat transfer. It then compares the findings regarding Nusselt number enhancement to a reduced-order model on a two-dimensional domain in the wake of the bubble. The model solves the advective-diffusion equation assuming a velocity field consistent with fully developed channel flow in the absence of the bubble. The response of the uniform-heat-generation upper wall is included. The model assumes a temperature profile directly behind the bubble which represents a well-mixed region produced by the passage of the bubble.
The significant wake heat transfer enhancement and its decay with distance from the bubble documented by the simulation were captured by the reduced-order model. However, the channel surface temperature recovered in a much shorter distance in the simulation compared to the reduced-order model. This difference is attributed to the omission of transverse conduction within the heated surface in the two-dimensional model. Beyond approximately one bubble diameter into the bubble wake, the complex flow structures are replaced by the momentum field of the precursor channel flow. However, the properties and thickness of the heated upper channel wall govern the heat transfer for many bubble diameters behind the bubble.
Evaluation of Heat Transfer Performance of a Spiral Microfluidic Heatsink and Heat Exchanger Device
Authors: Virik Niven Singh , Marshall Samuel D. , Arayanarakool Rerngchai , See Hian Hian , Wang Heng , Lee Poh Seng , Yu Peter Chen Chao 
Published: August 2018

Developments in micro-technology have seen vast improvements in the design and the thermal performance of heat sinks and heat exchangers, particularly in the case of spiral microfluidic devices which deals with the flow of liquids inside curved micrometer-sized channels. The current research deals with a specially designed curved microfluidic channel used to employ the fluid mixing characteristics of Dean vortices and thus transfer heat more efficiently. This curved microfluidic channel is deployed as a spiral channel to create an effective heat sink and a heat exchanger.
The novel micro heat exchanger is built by integrating two or more of the specially designed microfluidic heat sink layers. For the ease of fabricating the microchannels, these devices are polymer-based. In this paper, the thermal performance of the spiral microfluidic devices is analyzed numerically and experimentally using a range of flow rates where Thermal Performance Factor is used to find a balanced point between heat transfer and pressure drop. The spiral heat exchange device proves to be an effective thermal transport system with the introduction of curved channels in the devices where the presence of Dean vortices in the system is observed, especially at lower flow rates. It can be observed that by increasing the number of layers, the thermal performance is greatly improved. This is due to the higher surface area with increasing number of layers, as well as a parallel flow structure through the layers.
These results serve as a design parameter for developing microchannel-based heat transfer devices that can achieve high efficiency of heat and mass transfer. Further heat sink and heat exchanger design improvements are discussed.
Acute ultraviolet radiation exposure attenuates nitric oxide-mediated vasodilation in the cutaneous microvasculature of healthy humans
Authors: Wolf S. Tony , Stanhewicz Anna E. , Jablonski Nina G. , Kenney W. Larry 
Published: August 2018

5-Methyltetrahydrofolate (5-MTHF) is important for nitric oxide (NO)-mediated cutaneous microvascular vasodilation. Ultraviolet B (UVB) radiation may deplete 5-MTHF, either directly or via production of reactive oxygen species (ROS), decreasing NO-mediated vasodilation. We hypothesized that 1) acute UVB exposure would attenuate NO-dependent cutaneous vasodilation, 2) local perfusion of 5-MTHF or ascorbate (ASC) (antioxidant) would augment NO-dependent vasodilation after UVB, and 3) darker skin pigmentation would be UVB-protective. Intradermal microdialysis fibers ( n = 3) placed in each forearm of 22 healthy young adults (23 ± 1 yr; 8M/14F) locally delivered lactated Ringer’s (control), 5 mM 5-MTHF, or 10 mM ASC. One arm was UVB-exposed (300 mJ/cm2), and the other served as a nonexposed control (CON). Following UVB exposure, a standardized local heating (42°C) protocol induced cutaneous vasodilation. After attaining a plateau blood flow, 15 mM NG-nitro-l-arginine methyl ester (nitric oxide synthase inhibiter) was infused at all sites to quantify the NO contribution. Red cell flux was measured at each site by laser-Doppler flowmetry (LDF), and cutaneous vascular conductance (CVC = LDF/mean arterial pressure) was expressed as a percentage of maximum (28 mM sodium nitroprusside + 43°C). UVB attenuated NO-mediated vasodilation compared with CON (23.1 ± 3.6 vs. 33.9 ± 3.4%; P = 0.001). Delivery of 5-MTHF or ASC improved NO-mediated vasodilation versus lactated Ringer’s in the UVB-exposed arm (MTHF: 30.1 ± 4.8% vs. 23.1 ± 3.8%; P = 0.03; ASC: 30.9 ± 4.3% vs. 23.1 ± 3.8%; P = 0.02). Neither treatment affected the response in the nonexposed arm ( P ≥ 0.09). Skin pigmentation (melanin index) was not predictive of the UVB response ( P ≥ 0.34). These data suggest that acute UVB exposure attenuates NO-mediated vasodilation via direct and/or ROS-induced reductions in 5-MTHF, independent of skin pigmentation. NEW & NOTEWORTHY Endothelial-derived nitric oxide (NO) contributes to normal healthy function of the human cutaneous microvasculature. Bioavailability of 5-methyltetrahydrofolate (5-MTHF) is important for the production of NO. Ultraviolet (UV) radiation exposure, specifically UVB, may deplete cutaneous 5-MTHF, thereby reducing NO-mediated microvascular function. Our findings suggest that acute UVB exposure attenuates NO-mediated vasodilation of the cutaneous microvasculature via degradation of 5-MTHF. These findings advance our understanding of the potential negative health impacts of acute UV exposure.
Functional Ex Vivo Assay Reveals Homologous Recombination Deficiency in Breast Cancer Beyond BRCA Gene Defects
Authors: Meijer Titia G. , Verkaik Nicole S. , Sieuwerts Anieta M. , van Riet Job , Naipal Kishan A.T. , van Deurzen Carolien H.M. , den Bakker Michael A. , Sleddens Hein F.B.M. , Dubbink Hendrikus-Jan , den Toom T. Dorine , Dinjens Winand N.M. , Lips Esther , Nederlof Petra M. , Smid Marcel , van de Werken Harmen J.G. , Kanaar Roland , Martens John W.M. , Jager Agnes , van Gent Dik C. 
Published: August 2018

Abstract

Purpose:
Tumors of germline BRCA1/2 mutated carriers show homologous recombination (HR) deficiency (HRD), resulting in impaired DNA double-strand break (DSB) repair and high sensitivity to PARP inhibitors. Although this therapy is expected to be effective beyond germline BRCA1/2 mutated carriers, a robust validated test to detect HRD tumors is lacking. In this study, we therefore evaluated a functional HR assay exploiting the formation of RAD51 foci in proliferating cells after ex vivo irradiation of fresh breast cancer tissue: the recombination REpair CAPacity (RECAP) test.

Experimental Design:
Fresh samples of 170 primary breast cancer were analyzed using the RECAP test. The molecular explanation for the HRD phenotype was investigated by exploring BRCA deficiencies, mutational signatures, tumor-infiltrating lymphocytes (TIL), and microsatellite instability (MSI).

Results:
RECAP was completed successfully in 125 of 170 samples (74%). Twenty-four tumors showed HRD (19%), whereas six tumors were HR intermediate (HRi; 5%). HRD was explained by BRCA deficiencies (mutations, promoter hypermethylation, deletions) in 16 cases, whereas seven HRD tumors were non-BRCA related. HRD tumors showed an increased incidence of high TIL counts (P = 0.023) compared with HR proficient (HRP) tumors and MSI was more frequently observed in the HRD group (2/20, 10%) than expected in breast cancer (1%; P = 0.017).

Conclusions:
RECAP is a robust functional HR assay detecting both BRCA1/2-deficient and BRCA1/2-proficient HRD tumors. Functional assessment of HR in a pseudo-diagnostic setting is achievable and produces robust and interpretable results.
PSMA Ligand PET/MRI for Primary Prostate Cancer: Staging Performance and Clinical Impact
Authors: Grubmüller Bernhard , Baltzer Pascal , Hartenbach Sabrina , D’Andrea David , Helbich Thomas H. , Haug Alexander R. , Goldner Gregor M. , Wadsak Wolfgang , Pfaff Sarah , Mitterhauser Markus , Balber Theresa , Berroteran-Infante Neydher , Grahovac Marko , Babich John , Seitz Christian , Kramer Gero , Susani Martin , Mazal Peter , Kenner Lukas , Shariat Shahrokh F. , Hacker Marcus , Hartenbach Markus 
Published: August 2018

Abstract

Purpose:
Primary staging of prostate cancer relies on modalities, which are limited. We evaluate simultaneous [68Ga]Ga-PSMA-11 PET (PSMA-PET)/MRI as a new diagnostic method for primary tumor–node–metastasis staging compared with histology and its impact on therapeutic decisions.

Experimental Design:
We investigated 122 patients with PSMA-PET/MRI prior to planned radical prostatectomy (RP). Primary endpoint was the accuracy of PSMA-PET/MRI in tumor staging as compared with staging-relevant histology. In addition, a multidisciplinary team reassessed the initial therapeutic approach to evaluate its impact on the therapeutic management.

Results:
PSMA-PET/MRI correctly identified prostate cancer in 119 of 122 patients (97.5%). Eighty-one patients were treated with RP and pelvic lymphadenectomy. The accuracy for T staging was 82.5% [95% confidence interval (CI), 73–90; P &lt; 0.001], for T2 stage was 85% (95% CI, 71–94; P &lt; 0.001), for T3a stage was 79% (95% CI, 43–85; P &lt; 0.001), for T3b stage was 94% (95% CI, 73–100; P &lt; 0.001), and for N1 stage was 93% (95% CI, 84–98; P &lt; 0.001). PSMA-PET/MRI changed the therapeutic strategy in 28.7% of the patients with either the onset of systemic therapy/radiotherapy (n = 16) or active surveillance (n = 19).

Conclusions:
PSMA-PET/MRI can provide an accurate staging of newly diagnosed prostate cancer. In addition, treatment strategies were changed in almost a third of the patients due to the information of this hybrid imaging technique.
Early-Life Alcohol Intake and High-Grade Prostate Cancer: Results from an Equal-Access, Racially Diverse Biopsy Cohort
Authors: Michael Jamie , Howard Lauren E. , Markt Sarah C. , De Hoedt Amanda , Bailey Charlotte , Mucci Lorelei A. , Freedland Stephen J. , Allott Emma H. 
Published: August 2018

Abstract
Epidemiologic evidence for an association between alcohol and prostate cancer is mixed. Moreover, there is a lack of research investigating early-life alcohol intake as a risk factor for either overall or high-grade prostate cancer. We examined lifetime alcohol intake in association with prostate cancer diagnosis in an equal-access, racially diverse prostate biopsy cohort. Men undergoing prostate biopsy at the Durham Veterans Affairs Medical Center from 2007 to 2018 completed a survey indicating average number of alcoholic beverages consumed per week [categorized as none (ref), 1–6, ≥7] during each decade of life. Multivariable logistic regression was used to test the association between alcohol intake across decades and diagnosis of overall, low-grade [grade group (GG) 1–2] and high-grade prostate cancer (GG 3–5). Of 650 men ages 49–89 who underwent biopsy, 325 were diagnosed with prostate cancer, 238 with low-grade and 88 with high-grade disease. Relative to nondrinkers, men who consumed ≥7 drinks/week at ages 15 to 19 had increased odds of high-grade prostate cancer diagnosis (OR = 3.21, Ptrend = 0.020), with similar findings for ages 20 to 29, 30 to 39, and 40 to 49. Consistent with these results, men in the upper tertile of cumulative lifetime intake had increased odds of high-grade prostate cancer diagnosis (OR = 3.20, Ptrend = 0.003). In contrast, current alcohol intake was not associated with prostate cancer. In conclusion, among men undergoing prostate biopsy, heavier alcohol intake earlier in life and higher cumulative lifetime intake were positively associated with high-grade prostate cancer diagnosis, while current intake was unrelated to prostate cancer. Our findings suggest that earlier-life alcohol intake should be explored as a potential risk factor for high-grade prostate cancer. Cancer Prev Res; 11(10); 621–8. ©2018 AACR.
Morphological and molecular characterisation of Spirinia antipodea Leduc n. sp. (Nematoda: Desmodoridae), a cryptic species related to S. parasitifera, from the coast of New Zealand
Authors: Leduc Daniel , Zhao Zeng Qi 
Published: August 2018

SummarySpirinia parasitiferais a common nematode species recorded from coastal habitats of the White, North and Barents Seas, the Northwest Atlantic, the Maldives and Australia, and exhibits a high degree of variability in some morphological characters. For these reasons it has been suggested thatS. parasitiferais a species complex comprised of several distinct but potentially cryptic species. However, no study has yet combined molecular and morphological approaches to verify this assertion. Here, we describeS. antipodean. sp., a species morphologically very similar toS. parasitifera, from the coast of New Zealand.Spirinia antipodean. sp. differs from the original description ofS. parasitiferaas well as subsequent descriptions by other authors in at least one body dimension, but no single trait differs consistently between the New Zealand specimens and all descriptions ofS. parasitifera. Phylogenetic analyses showed that the new species is distinct from other species of the genus, includingS. parasitiferaspecimens sampled near the type locality. TheS. antipodean. sp. SSU sequence differed from otherSpiriniasequence by 2.1-5.3%, whilst D2-D3 of LSU sequences differed by 12.5-18.9%. The consensus SSU tree also recovered three distinctS. parasitiferaclades, which provides support for the existence of a species complex. Because it is not possible to determine whether the variability in morphological characters observed among descriptions ofS. parasitiferais intra- or interspecific, and therefore to determine which trait can reliably be used to differentiate betweenS. antipodean. sp. andS. parasitifera, the new species is best differentiated fromS. parasitiferaand other closely related species based on SSU sequences rather than morphological characters.
Hurricane Bonnie (1998): Maintaining Intensity during High Vertical Wind Shear and an Eyewall Replacement Cycle
Authors: Dougherty Erin M. , Molinari John , Rogers Robert F. , Zhang Jun A. , Kossin James P. 
Published: August 2018

Abstract
Hurricane Bonnie (1998) was an unusually resilient hurricane that maintained a steady-state intensity while experiencing strong (12–16 m s−1) vertical wind shear and an eyewall replacement cycle. This remarkable behavior was examined using observations from flight-level data, microwave imagery, radar, and dropsondes over the 2-day period encompassing these events. Similar to other observed eyewall replacement cycles, Bonnie exhibited the development, strengthening, and dominance of a secondary eyewall while a primary eyewall decayed. However, Bonnie’s structure was highly asymmetric because of the large vertical wind shear, in contrast to the more symmetric structures observed in other hurricanes undergoing eyewall replacement cycles. It is hypothesized that the unusual nature of Bonnie’s evolution arose as a result of an increase in vertical wind shear from 2 to 12 m s−1 even as the storm intensified to a major hurricane in the presence of high ambient sea surface temperatures. These circumstances allowed for the development of outer rainbands with intense convection downshear, where the formation of the outer eyewall commenced. In addition, the circulation broadened considerably during this time. The secondary eyewall developed within a well-defined beta skirt in the radial velocity profile, consistent with an earlier theory. Despite the large ambient vertical wind shear, the outer eyewall steadily extended upshear, supported by 35% larger surface wind speed upshear than downshear. The larger radius of maximum winds during and after the eyewall replacement cycle might have aided Bonnie’s resiliency directly, but also increased the likelihood that diabatic heating would fall inside the radius of maximum winds.
Weekly Rounding With the MICU Team: Description of a Clinical Ethics Project
Authors: Vig Elizabeth K. 
Published: August 2018

Context: Patients in medical intensive care units (MICUs) are medically complex. This complexity can lead to uncertainty about patient goals and prognosis. Ethical dilemmas arise when there is uncertainty about the clinically and ethically appropriate actions for managing seriously ill patients. Ethics and palliative care involvement may promote improved quality of care and reduced staff moral distress. Project Description: In this clinical project, a physician with ethics, palliative care, and geriatrics expertise attended morning rounds with the MICU team weekly. Data on the logistics and impact from the first 2 years of the project were collected. Project Logistics and Preliminary Impact: Rounds lasted approximately 1.75 hours per week. The rounder was present for discussion of approximately 200 patients per year and made comments on nearly half of the patients. The comments were categorized as 25% ethics, 40% palliative care, 10% geriatrics, and 25% a combination or other topic. Attending physicians rated the project as helpful. The number of ethics and palliative care consults from the MICU increased in the first 2 years. Downstream impact has included a dietician reviewing Physician Orders for Life Sustaining Treatment forms with teams throughout the hospital and routine review of advance directives of newly admitted patients. Discussion: Weekly MICU rounding provides an opportunity to briefly teach staff and trainees about relevant ethics, palliative care, and geriatrics issues. It also provides a forum for discussion of ethically challenging cases. Considerations when starting a similar program are discussed.
Correlation of Radiographic Measurements With Patient-Centered Outcomes in Hallux Valgus Surgery
Authors: Matthews Michael , Klein Erin , Youssef Angie , Weil Lowell , Sorensen Matthew , Weil Lowell S. , Fleischer Adam 
Published: August 2018

Background: Evaluation of patients undergoing hallux valgus surgery has historically emphasized radiographic angles and relationships. However, patient-reported outcomes are increasingly important as health care systems trend towards a “value-based” delivery approach. Methods: We conducted a retrospective analysis of pre-existing data in our practice to examine whether patient-reported outcomes after bunion surgery, determined via Foot and Ankle Outcome Scores (FAOS), correlated with radiographic parameters commonly measured in hallux valgus deformity. Pearson correlation statistics and simple and multiple linear regression models were used to identify important radiographic predictors. There were 80 patients (80 feet) with mean follow-up of 59.3 ± 11.6 weeks (median 55, range 45.7-96.3 weeks) with complete data. Results: No radiographic measurement/variable achieved anything more than a weak correlation with any of the FAOS subscale scores at final follow-up; the study’s best was postoperative first-second intermetatarsal (IM) angle with sports and recreation scores ( r = −0.328, P = .005). There was no correlation found between change in hallux valgus angle, change in first-second IM angle, magnitude of preoperative hallux valgus angle or magnitude of preoperative first-second IM angle ( P > .05 for all). Furthermore, none of the study’s final multivariable models achieved an R2 > 0.24, and nearly all fell between 0.10 and 0.17. Conclusion: We conclude that radiographic angles were not well correlated with patient-centered outcomes in hallux valgus surgery. This study calls into question the current emphasis that is placed on x-ray values both pre- and postoperatively. Level of clinical evidence: Level III, comparative study.