[Epidemiological investigation of constipation in urban areas of Hangzhou, China]

Objective: To determine the prevalence and risk factors of constipation in Hangzhou urban areas by analyzing data from a recent epidemiological survey. Methods: From August 2022 to June 2023, a cross-sectional survey was conducted on 43 communities on eight streets in suburbs of Hangzhou, including Wangjiang, Sijiqing, Puyan, Changhe, Ziyang, Xiaoshanchengxiang, Zhuantang, and Banshan. Written questionnaires were filled out face to face by community doctors. The prevalence of constipation was investigated using a combination of the Bristol stool typing method and the Rome IV criteria. The risk factors for constipation were analyzed using multivariate logistic regression analysis. Results: The study cohort comprised 10,479 participants, 5551 of whom were male (53.0%) and 4928 female (47.0%). The overall prevalence of constipation was 10.6% (1107/10,479). The prevalence was 11.0% (613/5551) for male and 10.0% (494/4928) for female participants; this difference is not statistically significant (P>0.05).There were no significant differences in the prevalence of constipation between different categories of body mass index (P>0.05). The prevalence of constipation was highest in individuals aged 70 years and above, accounting for 15.4% (264/1717) of all cases. There were significant differences in the prevalence of constipation between different occupations, marital statuses, and educational levels (P<0.001). Patients with hypertension or diabetes mellitus had a higher prevalence of constipation than those without these conditions, those who had been taking long-term medication had a higher prevalence of constipation than those who did not, parents of children with constipation had a higher prevalence of constipation than those with children who did not have constipation, and there were other significant differences in various variables (P<0.001). Multivariate logistic regression analysis of modifiable factors revealed that eating less fruit (OR=1.284, 95%CI: 1.061-1.553, P=0.010), liking spicy and salty food (OR=1.234, 95%CI: 1.039-1.466, P=0.016), sleeping for too long (OR=1.644, 95%CI: 1.260-2.144, P<0.001), irregular sleep patterns (OR=1.370, 95%CI: 1.127-1.665, P=0.002) and minimal exercise (OR=1.388, 95% CI: 1.168-1.649, P<0.001) were all risk factors for constipation; whereas mix diets (OR=0.709,95%CI:0.608-0.826, P<0.001), meat diets (OR=0.604,95%CI: 0.495-0.736, P<0.001), moderate alcohol consumption (OR=0.659, 95% CI: 0.534-0.812, P<0.001), less or no drinking (OR=0.523, 95% CI: 0.428-0.638, P<0.001), and non-smoking (OR=0.819, 95%CI:0.674-0.995, P<0.001) protected against constipation. We found no association between dietary preferences and the risk of constipation (refined grains: OR=1.147, 95%CI:0.944-1.393, P=0.167; no specific preference: OR=0.935, 95%CI:0.783-1.117, P=0.459). The rate of agreement between self-evaluation of constipation by the respondents and objective criteria was higher for negatives (95.8%) than for positives (38.0%). Conclusion: The prevalence of constipation is relatively high in the urban population of Hangzhou. A good lifestyle and diet can significantly reduce its incidence. There should be more emphasis on preventive education, promotion of prevention of constipation, and advocacy for a healthy lifestyle.

[Comparison of mid-cheek tumors endoscopically assisted dissection between a single preauricular or transoral incision]

Objective: To summarize the preliminary experience of endoscopically assisted mid-cheek benign tumor resection using a single preauricular or transoral incision and to evaluate its indications, advantages, and disadvantages. Methods: Thirty-six patients with benign mid-cheek tumors were prospectively enrolled, including 11 males and 25 females, aged (37.2±15.9) years and ranged from 11 to 65 years old. The patients were randomly divided into two groups: endoscope-assisted tumor dissections through a single preauricular incision (19 cases) or transoral incision (17 cases). Their surgical approaches were introduced, and the tumor long-axis length, incision length, operative time, estimated intraoperative bleeding, postoperative drainage amount and time, aesthetic satisfaction, perioperative complications, and follow-up were recorded and analyzed. Results: The difference between the tumor long-axis lengths in the preauricular group [(2.2±0.9) cm] and the transoral group [(2.1±0.7) cm] was not statistically significant (t=0.46, P=0.687), and all surgical procedures were completed as planned. There was no significant difference in the incision size (t=1.57, P=0.100) or operative time (t=0.44, P=0.736). Compared with the preauricular group [(30.8±8.7) ml], transoral incision [(23.6±8.9) ml] reduced intraoperative blood loss (t=2.97, P=0.006) and improved aesthetic pleasure (t=3.44, P=0.015). Two cases of earlobe numbness and one case of temporary facial palsy were observed in the preauricular group; two cases of postoperative effusion were noted in the transoral group, and no signs of nerve injury were detected. No tumor recurrence was found during the 1-54-month of follow-up. perioperative complications. Conclusions: Endoscopic-assisted preauricular or transoral incision for dissecting mid-cheek benign tumors provides excellent aesthetic and minimally invasive results, reducing complications and obtaining satisfactory aesthetic results.

Silicon optrode array with monolithically integrated SU-8 waveguide and single LED light source

This paper presents a conventional LED (light emitting diode) and polymer waveguide coupled silicon optrode array. Unique lens design at the waveguide inlet enables a high light coupling efficiency with a single LED light source, and provides small power consumption compatible with a wireless optogenetic neuromodulation system. To increase the light intensity at the waveguide tip, a lensed waveguide is fabricated with epoxy-based photoresist SU-8, which has a plano-convex lens shape at the waveguide inlet to focus the light in the horizontal direction. In addition, a cylindrical lens is assembled in front of the waveguide inlet to focus the source light in the vertical direction. The glass cylindrical lens and SU-8 plano-convex lens increased the light coupling efficiency by 6.7 dB and 6.6 dB, respectively. The fabricated 1×4 array of optrodes is assembled with a single LED with 465 nm wavelength, which produces a light intensity of approximately 2.7 mW/mm2 at the SU-8 waveguide outlet when 50 mA input current is applied to the LED. Each optrode has four recording electrodes at the SU-8 waveguide outlet. The average impedance of the iridium oxide (IrOx) electroplated recording electrodes is 43.6 kΩ. In-vivo experiment at the hippocampus region CA1 and CA2 demonstrated the capability of optical stimulation and neural signal recording through the LED and SU-8 waveguide coupled silicon optrode array.

Implantable Optrode Array for Optogenetic Modulation and Electrical Neural Recording

During the last decade, optogenetics has become an essential tool for neuroscience research due to its unrivaled feature of cell-type-specific neuromodulation. There have been several technological advances in light delivery devices. Among them, the combination of optogenetics and electrophysiology provides an opportunity for facilitating optogenetic approaches. In this study, a novel design of an optrode array was proposed for realizing optical modulation and electrophysiological recording. A 4 × 4 optrode array and five-channel recording electrodes were assembled as a disposable part, while a reusable part comprised an LED (light-emitting diode) source and a power line. After the characterization of the intensity of the light delivered at the fiber tips, in vivo animal experiment was performed with transgenic mice expressing channelrhodopsin, showing the effectiveness of optical activation and neural recording.

Design optimization of a 6.4 mm-diameter electromagnetic 2D scanning micromirror

We present the design optimization, fabrication, and analysis of an electromagnetic biaxial scanning micromirror with 6.4 mm-diameter. The scanner is composed of a micromirror supported by two concentric gimbal structures with unique single turn coil. A cylindrical permanent magnet assembly is placed under the micromirror to provide a radial magnetic field for actuation. Lumped element model parameters and magnetic circuit have been optimized to maximize the driving torque. Fabricated micromirror has been actuated at 300 Hz and 1,010 Hz and maximum optical scan angle of 25.6° and 35.3° have been obtained for the vertical and horizontal scans, respectively. Crosstalk during the actuation has been analyzed, and improved models have been proposed to reduce the crosstalk.

Reliability Analysis of an Epileptic Seizure Detector Powered by an Energy Harvester

Due to a limited lifetime of a battery, energy harvesters have been studied as alternative energy sources for implantable biomedical devices such as an implantable stimulator for epileptic seizure suppression. However, energy harvesters have weakness in providing stable power. We designed a neural recording circuit powered solely by a piezoelectric energy harvester, and applied its output to a seizure detector to analyze the reliability of the recorded signal. Performance of the seizure detector was evaluated. We found that the average time differences between with and without voltage variances were about 0.05 s under regular vibrations and about 0.07 s under irregular vibrations, respectively. The ratio of average true positive alarm period varied within about 0.02% under regular vibrations and 0.029% under irregular vibrations, respectively. The ratio of average false positive alarm period varied within about 0.004% under regular vibrations and 0.014% under irregular vibrations, respectively. This paper presents a reliability analysis of an epileptic seizure detector with a neural signal recording circuit powered by a piezoelectric energy harvester. The results showed that a supply voltage variance within ±10% could be acceptable for reliable operation of a seizure detector.

Solution-Processed Organic Photodetector Using Hafnium Oxide as an Electron Blocking Layer

Organic photodetector (OPD) performance is affected significantly by leakage current. In this study, to decrease OPD leakage current, we introduced hafnium oxide as an electron blocking material, using a solution fabrication process. We fabricated an OPD consisting of ITO/HfO₂/PCHT:PC₆₀BM/Yb/Al, and measured its J-V characteristics, external quantum efficiency, and transient photocurrents. We found that the thickness of the hafnium oxide layer affected the detectivity of the prepared OPD. In particular, a device having an ultrathin hafnium oxide film (5.5 nm thick) exhibited a high on-off current ratio of up to 2.26 × 10⁵ at -1 V, which is two times higher than that of a device having a PEDOT:PSS electron blocking layer.

Multi-wavelength light emitting diode-based disposable optrode array for in vivo optogenetic modulation

We present a light emitting diode (LED)-based optical waveguide array that can optogenetically modulate genetically targeted neurons in the brain. The reusable part of the system consists of control electronics and conventional multi-wavelength LED. The disposable part comprises optical fibers assembled with microlens array fabricated on a silicon die. Both parts can be easily assembled and separated by snap fit structure. Measured light intensity is 3.35 mW/mm² at 469 nm and 0.29 mW/mm² at 590 nm when the applied current is 80 mA. In all the tested conditions, the light-induced temperature rise is under 0.5°C and over 90% of the relative light intensity is maintained at 2 mm-distance from the fiber tips. We further tested the efficiency of the optical array in vivo at 469 nm. When the optical array delivers light stimulation on to the visual cortex of a mouse expressing channelrhodopsin-2, the neural activity is significantly increased. The light-driven neural activity is successfully transformed into a percept of the mouse, showing significant learning of the task detecting the cortical stimulation. Our results demonstrate that the proposed optical array interfaces well with the neural circuits in vivo and the system is applicable to guide animal behaviors.

MEMS vibrational energy harvesters

In this paper, we look into the fundamental mechanism to retrieve the power from physical vibrations by using microelectromechanical systems (MEMS) energy harvesters. An analytical model is presented for the velocity-damped resonant generator (VDRG) that delivers electrical power through the power enhancement mechanism using the mechanical resonance of a suspended mass. Deliverable power is also analytically discussed with respect to the theoretical limit, and a view to understand the VDRG behaviors is presented in association with the impedance matching condition and the quality factors. Mechano-electric power conversions including electrostatic induction, electromagnetic induction, and piezoelectric effect are discussed to study the scaling effect. Recent examples of MEMS VDRGs are reviewed and evaluated in terms of the power density.

Electromagnetic biaxial vector scanner using radial magnetic field

We present an electromagnetic biaxial vector-graphic scanning micromirror. In contrast to conventional electromagnetic actuators using linear magnetic field, proposed device utilizes a radial magnetic field and uniquely designed current paths to enable the 2 degree-of-freedom scanning motion. As the radial field is generated by concentrically assembled magnets placed under the scanner die, large driving torque can be generated without the aid of hermetic packaging and relatively small device volume can be achieved. Mechanical half scan angle of 6.43° and 4.20° have been achieved at DC current of 250mA and 350mA for horizontal and vertical scans, respectively. Forced actuation along both scan axes has been realized by feedback control.

Electromagnetic biaxial microscanner with mechanical amplification at resonance

We present the design, fabrication, and measurement results of an electromagnetic biaxial microscanner with mechanical amplification mechanism. A gimbaled scanner with two distinct single-crystal silicon layer thicknesses and integrated copper coils has been fabricated with combination of surface and bulk micromachining processes. A magnet assembly consisting of an array of permanent magnets and a pole piece has been placed under the substrate to provide high strength lateral magnetic field oriented 45° to two perpendicular scanning axes. Micromirror has been supported by additional gimbal to implement a mechanical amplification. A 1.2mm-diameter mirror with aluminum reflective surface has been actuated at 60Hz for vertical scan and at 21kHz for horizontal scan. Maximum scan angle of 36.12° at 21.19kHz and 17.62° at 60Hz have been obtained for horizontal and vertical scans, respectively.

Promoter-dependent and -independent activation of insulin-like growth factor binding protein-5 gene expression by prostaglandin E2 in primary rat osteoblasts

Insulin-like growth factor (IGF) action is mediated by high affinity cell surface IGF receptors and modulated by a family of secreted IGF binding proteins (IGFBPs). IGFBP-5, the most conserved of six IGFBPs characterized to date, uniquely potentiates the anabolic actions of IGF-I for skeletal cells. In osteoblasts, IGFBP-5 production is stimulated by prostaglandin E2 (PGE2), a local factor that mediates certain effects induced by parathyroid hormone, cytokines such as interleukin-1 and transforming growth factor-beta, and mechanical strain. In this study, we show that transcriptional and post-transcriptional events initiated by PGE2 collaborate to enhance IGFBP-5 gene expression in primary fetal rat osteoblast cultures. PGE2 treatment stimulated up to a 7-fold rise in steady-state levels of IGFBP-5 mRNA throughout 32 h of incubation. Analysis of nascent IGFBP-5 mRNA suggested that PGE2 had only a modest stimulatory effect on IGFBP-5 gene transcription, and transient transfection studies with IGFBP-5 promoter-reporter genes confirmed that PGE2 enhanced promoter activity by approximately 2-fold. Similar stimulatory effects were seen with forskolin. A DNA fragment with only 51 base pairs of the 5'-flanking sequence retained hormonal responsiveness, which may be mediated by a binding site for transcription factor AP-2 located at positions -44 to -36 in the proximal IGFBP-5 promoter. Incubation of osteoblasts with the mRNA transcriptional inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole demonstrated that PGE2 enhanced IGFBP-5 mRNA stability by 2-fold, increasing the t1/2 from 9 to 18 h. The effects of PGE2 on steady-state IGFBP-5 transcripts were abrogated by preincubating cells with cycloheximide, indicating that the effects of PGE2 on both gene transcription and mRNA stability required ongoing protein synthesis. Therefore, both promoter-dependent and -independent pathways converge to enhance IGFBP-5 gene expression in response to PGE2 in osteoblasts.

Granular cell tumour of the neurohypophysis

Granular cell tumours of the neurohypophysis are very rare. Their aetiology and nature are uncertain. Most investigators consider them to arise from pituicytes or Schwann cells of the posterior lobe of the hypophysis. They are found most commonly in older people. A surgically proven symptomatic case is reported.