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Control strategies for variable-air-volume (VAV) air conditioning significantly affect both the air quality within buildings and the consumption of building energy. Current control techniques effectively regulate room temperature using feedback on temperature discrepancies, yet they also elevate the wear on terminal devices and boost the energy usage of the supply fan. In this paper, the hysteresis and inertia parameters of end air valves and supply fans under two seasonal conditions are derived from experimental data. Aiming at the problems of frequent switching of the end air valve, long total switching stroke, and high energy consumption of the air supply fan, a fuzzy PI regulation method is proposed based on the original pressure-independent series PI regulation, which effectively solves the above problems. Initially, data on how room temperature reacts to changes in air supply fan speed and the position of end air valves during winter and summer were gathered. Following model identification, parameters for various seasonal conditions were determined. Secondly, the roles of different components in the variable-air-volume regulation process were investigated. Investigations revealed that within pressure-independent variable-air-volume control, the supply fan and end air valve emerged as the primary subjects of the study. A double-closed-loop control with the speed control of the supply fan as the outer loop and the opening control of the end air valve as the inner loop was adopted. Compared with the traditional serial PI regulation, the room temperature error of this method was increased, but it reduced the total stroke of the valve by more than 43%, which greatly reduced the valve’s loss and noise and saved more than 2.7% of the energy consumption of the air supply fan.

Study DesignBibliometric analysis.ObjectiveAnterior cervical discectomy and fusion (ACDF) is a typical surgical method in spine surgery and has progressed significantly in the last several decades. The purpose of this study is to determine how the 100 most-cited original articles on ACDF have been the most influential in this field by identifying and analyzing them.MethodsThe articles on ACDF were identified by searching the Thomson ISI Web of Science database on 30 May 2022. The 100 most-cited articles were selected according to specific criteria. The data extracted from the articles included title, publication date, total citations, journal name, first author, institutions, and keywords.ResultsThe total number of citations was 13,181, with a mean number of 131.81 ± 100.18. The publication dates ranged from 1994 to 2018. Most of these articles originated in the United States (68%) and were published in the 2000s (32%) and 2010s (48%). Spine published most of the articles (30%), followed by the Journal of Neurosurgery-Spine (16%), Spine Journal (14%), and European Spine Journal (13%). The most prolific author was Dr. Todd J Albert (n = 7), with 1,312 citations. The Texas Back Institute was the most productive institution (n = 10). The keywords ACDF, cervical spine, cervical spine, and fusion showed the highest degree of centrality.ConclusionOne hundred top-cited articles on ACDF were identified and analyzed in this study. We demonstrate that ACDF is a growing and popular area of research, with the focus of research varying through timeline trends. This will provide a comprehensive and detailed basis for spine surgeons to make clinical decisions and assimilate the research focus of cervical spine surgery.

BackgroundAn innovative prone cervical spine surgical position using a body-shape plaster bed with skull traction (BSPST) was compared with the traditional prone surgical position with horseshoe headrests.MethodsA total of 47 patients, undergoing posterior cervical spine surgery for cervical spine fracture, were retrospectively classified into two groups, the BSPST group (n = 24) and the traditional group (n = 23), and underwent a posterior instrumented fusion with or without decompression. Multiple indicators were used to evaluate the advantages of the BSPST compared with the traditional position.ResultsAll the operations went smoothly. The mean recovery rate was 56.30% in the BSPST group and 48.55% in the traditional group (p = 0.454), with no significant difference. The intraoperative blood loss (177.5 ml vs. 439.1 ml, p = 0.003) and the total incidence of complications (8.3 vs. 47.8%, p = 0.004) were significantly less in the BSPST group than in the traditional group. In addition, the BSPST position provided a greater comfort level for the operators and allowed convenient intraoperative radiography.ConclusionsThis is the first study to describe a combined body-shape plaster bed and skull traction as an innovative cervical spine-prone surgical position that is simple, safe, and stable, intraoperative traction direction adjustable, reproducible, and economical for posterior cervical spine fracture surgery, and potentially other cervical and upper dorsal spine surgeries in the prone position. Additionally, this position provides the surgeons with a comfortable surgical field and can be easily achieved in most orthopedic operation rooms.

The circadian clock controls the physiological functions of many tissues including the liver via an autoregulatory transcriptional−translational feedback loop, of which CLOCK is a core positive component. In addition, many studies have indicated that microRNAs (miRNAs) regulate liver function. However, how CLOCK-regulated miRNAs are linked to liver function remains largely unknown. In this study, miRNAs expression profiles were performed in the liver of ClockΔ19 mutant mice. Compared to wild type mice, totals of 61 and 57 putative CLOCK-regulated miRNAs were differentially expressed (fold change absolute value ≥2) at zeitgeber time 2 and zeitgeber time 14, respectively. According to the pathway analyses, the target genes of differentially expressed miRNAs were mainly involved in pathways in cancer, the PI3K-Akt signaling pathway and the MAPK signaling pathway. Protein−protein interaction analyses revealed that the hub genes were primarily associated with pathway in cancer and circadian rhythms. Expression validation showed that while the expression levels of miR-195 and miR-340 were up-regulated, the rhythms of these two miRNAs were always maintained. The expression level of nr1d2 mRNA was down-regulated. We identified a number of prospective CLOCK-regulated miRNAs that play roles in the various physiological processes of the liver, providing a reference to better understanding the potential regulatory mechanisms in the liver.