Development of a fully packaged passive thermal regulator.

Thermal regulators are devices that can adopt either the role of a thermal insulator or a thermal conductor, depending on the thermal input conditions, and play an increasingly important role in thermal management systems. In this study, we developed and tested a new passive thermal regulator design that operates around room temperature and achieves high switching ratios. Our regulator is structurally integer, scalable, orientation-independent, resistant to vibration, and can be easily integrated into existing thermal management solutions. The working principle of the passive regulator is simple yet effective, whereby an aluminum plug attached to a bimetallic strip enters and exists a wedge-shaped gap between two conductors. We demonstrate a switching ratio of ≈ 50 ( - 8 + 34 ) :1 for a fully packaged prototype (≈ 320 (± 200):1 for a non-packaged regulator) operated in the open laboratory environment. Through geometric optimization using numerical simulations, we show that a switching ratio of ≈ 100 ( - 15 + 18 ) :1 can be easily obtained, which can be further increased by increasing the cross-sectional area of the input conductor, hence increasing the ON-state heat transfer rate. The OFF-state thermal performance is much less sensitive to the size of the conductor, making the device highly scalable.

Predictive Value of Modified Frailty Index, Sarcopenia, Prognostic Nutritional Index, and Geriatric Nutritional Risk Index for Postoperative Complications in Oblique Lumbar Interbody Fusion Over 60 Years.

OBJECTIVE: Elderly patients undergoing spinal surgery are at an increased risk of morbidity and mortality. Evaluating frailty and preoperative status is crucial for predicting postoperative outcomes. This study aimed to assess the predictive value of the modified Frailty Index (mFI), sarcopenia, Prognostic Nutritional Index (PNI), and Geriatric Nutritional Risk Index (GNRI) in determining postoperative complications in patients undergoing oblique lumbar interbody fusion (OLIF) over 60 years. METHODS: Preoperative risk factors were assessed using 11 variables, including mFI, PNI, and GNRI. Complication rates were compared among nonfrail (mFI=0; n=50), prefrail (mFI=0.09-0.18; n=144), and frail (mFI ≥0.27; n=80) patients. Demographic and perioperative variables were compared between the complication and noncomplication groups. The incidence of complications was the primary outcome measure. RESULTS: Complications occurred in 36 of 274 patients (13.1%). The frail group exhibited a significantly higher incidence of pneumonia than the nonfrail and prefrail groups. The complication group displayed significant differences in several variables, including age, fusion level, albumin level, lymphocyte count, platelet count, creatinine level, and estimated blood loss. Moreover, mFI, PNI, and GNRI differed significantly between the complication and noncomplication groups. CONCLUSIONS: MFI, PNI, and GNRI can be useful for predicting postoperative morbidity and mortality in patients undergoing OLIF. These comprehensive assessment methods enable the identification of high-risk patients and the formulation of tailored strategies to enhance postoperative outcomes. Integrating mFI, PNI, and GNRI into the preoperative evaluation process can help health care providers proactively manage high-risk patients, thus improving the overall quality of care for elderly individuals undergoing OLIF.

Spinal Neurenteric Cyst of the Ventral Cervicothoracic Junction With Klippel-Feil Syndrome as a Symptom of Progressive Myelopathy: A Case Report.

Neurenteric cysts are rare and account for only 0.7%-1.3% of all spinal tumors. Spinal neurenteric cysts are associated with spina bifida, split-cord malformations, and Klippel-Feil syndrome, a rare congenital disorder characterized by fusion of two or more cervical vertebrae. Klippel-Feil syndrome is rarely accompanied by neurenteric cysts. In this case report, we describe a cervicothoracic junction neurenteric cyst associated with Klippel-Feil syndrome in a 30-year-old man who presented with a 2-month history of neck pain with radiation of pain into both arms and a 1-month history of weakness in the left arm. Magnetic resonance imaging (MRI) of the spine revealed an expansive intradural extramedullary cystic lesion anterior to the spinal cord at the cervicothoracic junction. The neurenteric cyst was removed using an anterior approach, accompanied by C5-C6 corpectomy. The patient's condition improved postoperatively, and he was discharged after postoperative MRI. Spinal neurenteric cysts should be considered in the differential diagnosis in cases of vertebral developmental abnormalities concurrent with intraspinal cysts.

Effect of Furosemide on Prevertebral Soft Tissue Swelling after Anterior Cervical Fusion: A Comparative Study with Dexamethasone.

STUDY DESIGN: Retrospective cohort study. PURPOSE: This study aimed to investigate the effect of furosemide on prevertebral soft tissue swelling (PSTS) after anterior cervical fusion (ACF) and compare it with the effect of dexamethasone. OVERVIEW OF LITERATURE: Postoperative PSTS is a common complication of ACF. Dexamethasone has been used for its treatment; however, its efficacy remains controversial. Furosemide may reduce PSTS if it is soft tissue edema; however, no studies have demonstrated the effect of furosemide on PSTS after ACF. METHODS: The symptomatic PSTS group received intravenous (IV) administration of dexamethasone or furosemide. The asymptomatic PSTS group did not receive any medication. Patients were divided into the control (no medication, n=31), Dexa (IV dexamethasone, n=25), and Furo (IV furosemide, n=28) groups. PSTS was checked daily with simple radiographs and medication-induced reductions in PSTS from its peak or after medication. RESULTS: The peak time (postoperative days) of PSTS in the control (2.27±0.47, p<0.05) and Dexa (1.91±0.54, p<0.01) groups were significantly later than that in the Furo group (1.38±0.74). PSTS was significantly lower in the Furo group than in the Dexa group from postoperative days 4 to 7 (p<0.05). PSTS reduction after the peak was significantly greater in the Furo group than in the control (p<0.01) and Dexa (p<0.01) groups. After starting the medication therapy, the Furo group showed a significantly greater reduction in PSTS than the Dexa group (p<0.01). No difference was found in symptom improvement among the three groups. CONCLUSIONS: If furosemide is used to reduce PSTS after ACF, it can effectively reduce symptoms.

Development of an indirect ELISA system for diagnosis of porcine edema disease using recombinant modified Stx2e antigen.

AIM: This study aimed to develop a sensitive and specific recombinant antigen protein indirect enzyme-linked immunosorbent assay (ELISA) kit to detect the Shiga toxin (Stx)-producing Escherichia coli (STEC) antibodies against porcine edema disease (ED). METHODS AND RESULTS: The recombinant antigen was co-expressed with the STEC-derived Stx2e A2-fragment and Stx2e B protein in E. coli BL21(DE3) pLysS cells and purified using maltose-binding protein open columns. We used a Shiga-like toxin 2 antibody to test the specificity of the recombinant antigen in an indirect ELISA, which was detected in antigen-coated wells but not in uncoated wells. We tested the indirect ELISA system using samples from the STEC-immunized pig group, the commercial swine farm group, and healthy aborted fetal pleural effusion group; five and twenty samples, respectively, were positive for STEC in the former, whereas all three samples were negative for STEC in the latter. CONCLUSIONS: This newly developed indirect ELISA may be a specific method for diagnosing STEC infections in pigs.