Programmable and Modularized Gas Sensor Integrated by 3D Printing.

The rapid advancement of intelligent manufacturing technology has enabled electronic equipment to achieve synergistic design and programmable optimization through computer-aided engineering. Three-dimensional (3D) printing, with the unique characteristics of near-net-shape forming and mold-free fabrication, serves as an effective medium for the materialization of digital designs into usable devices. This methodology is particularly applicable to gas sensors, where performance can be collaboratively optimized by the tailored design of each internal module including composition, microstructure, and architecture. Meanwhile, diverse 3D printing technologies can realize modularized fabrication according to the application requirements. The integration of artificial intelligence software systems further facilitates the output of precise and dependable signals. Simultaneously, the self-learning capabilities of the system also promote programmable optimization for the hardware, fostering continuous improvement of gas sensors for dynamic environments. This review investigates the latest studies on 3D-printed gas sensor devices and relevant components, elucidating the technical features and advantages of different 3D printing processes. A general testing framework for the performance evaluation of customized gas sensors is proposed. Additionally, it highlights the superiority and challenges of programmable and modularized gas sensors, providing a comprehensive reference for material adjustments, structure design, and process modifications for advanced gas sensor devices.

Hyper-crosslinked Isoporous Block Copolymer Membranes with Robust Solvent Resistance and Customized Pore Sizes for Precise Separation.

Isoporous block copolymer membranes are viewed as the next-generation separation membranes for their unique structures and urgent application in precise separation. However, an obvious weakness for such membranes is their poor solvent-resistance which limits their applications to aqueous solution, and isoporous membranes with superior solvent-resistance and tunable pore size have been rarely prepared before. Herein, self-supporting isoporous membranes with excellent solvent resistance are prepared by the facile yet robust hyper-crosslinking approach which is able to create a rigid network in whole membranes. The hyper-crosslinking is found to be a novel and non-destructive approach that does not change pore size and isoporous structure during the reaction, and the resulting hyper-crosslinked isoporous membranes display superior structural and separation stability to a broad range of solvents with varied polarities for months to years. More importantly, hyper-crosslinking has proved to be a universal strategy that is applicable to isoporous membranes with varied pore size and pore chemistry, offering an important opportunity to prepare solvent-resistant isoporous membranes with customizable pore size and pore functionality that are important to realize their accurate separations in organic solvents. This concept is demonstrated finally by precise and on-demand separation of nanoparticles with the prepared membranes.

[In Vitro Experimental Study on Hemodynamics of Transcatheter Aortic Valve Replacement].

The patient-specific aortic silicone model was established based on CTA data. The digital particle image velocimetry (DPIV) test method in the modified ViVitro pulsatile flow system was used to investigate the aortic hemodynamic performance and flow field characteristics before and after transcatheter aortic valve replacement (TAVR). The results showed that the hemodynamic parameters were consistent with the clinical data, which verified the accuracy of the model. From the comparative study of preoperative and postoperative effective orifice area (0.33 cm2 and 1.78 cm2), mean pressure difference (58 mmHg and 9 mmHg), percentage of regurgitation (52% and 8%), peak flow velocity (4.60 m/s and 1.81 m/s) and flow field distribution (eccentric jet and uniform jet), the immediate efficacy after TAVR is good. From the perspective of viscous shear stress and Reynolds shear stress, the risk of hemolysis and thrombotic problems was low in preoperative and postoperative patient-specific models. This study provides a set of reliable DPIV testing methods for aortic flow field, and provides biomechanical basis for the immediate and long-term effectiveness of TAVR from the perspective of hemodynamics and flow field characteristics. It has important application value in clinical diagnosis, surgical treatment and long-term evaluation.

Comparison of acquisition rate and agreement of axial length with two swept-source optical coherence tomographers and a partial coherence interferometer.

PURPOSE: To assess the acquisition rate and agreement of axial length (AL) measurements with the OA-2000, Anterion, and IOLMaster 500 in cataractous patients. METHODS: In total, 298 eyes of 191 cataractous patients were enrolled and scanned with the three devices in random order. The success rate of AL measurements per device was calculated and a chi-square test was utilized to identify the differences in acquisition rate between the three devices. Logistic regression analysis was applied to evaluate the association of different cataract types and severity with the AL measurement acquisition rate. Bland-Altman plots were mapped to appraise the agreement of AL values. RESULTS: AL measurements were successfully achieved in 288 eyes (96.64%) with the OA-2000, in 282 eyes (94.30%) with the Anteiron, and in 246 eyes (82.55%) with the IOLMaster 500. Significant differences in the acquisition rate were found between either of the SS-OCT devices and IOLMaster 500 by chi-square analysis (P < 0.001). No significant difference was noted between OA-2000 and Anterion. Increasing severity of posterior subcapsular cataract was associated with a higher failure rate with the IOLMaster 500. Bland-Altman analysis identified good agreement between the three biometers with narrow 95% limits of agreement. CONCLUSIONS: The OA-2000 and Anterion showed similarly higher acquisition rate of AL measurements than IOLMaster 500 in cataractous patients. Good agreement for AL values was found between the three biometers in cataractous patients.

Comparison of Balloon-Expandable Valve and Self-Expandable Valve in Transcatheter Aortic Valve Replacement: A Patient-Specific Numerical Study.

Transcatheter aortic valve replacement (TAVR) is a minimally invasive strategy for the treatment of aortic stenosis. The complex postoperative complications of TAVR were related to the type of implanted prosthetic valve, and the deep mechanism of this relationship may guide the clinical pre-operative planning. This technical brief developed a numerical method of TAVR to compare the outcome difference between balloon-expandable valve and self-expandable valve and predict the postoperative results. A complete patient-specific aortic model was reconstructed. Two prosthetic valves (balloon-expandable valve and self-expandable valve) were introduced to simulate the implantation procedure, and postprocedural function was studied with fluid-structure interaction method, respectively. Results showed similar stress distribution for two valves, but higher peak stress for balloon-expandable valve model. The balloon-expandable valve was associated with a better circular cross section and smaller paravalvular gaps area. Hemodynamic parameters like cardiac output, mean transvalvular pressure difference, and effective orifice area (EOA) of the balloon-expandable valve model were better than those of the self-expandable valve model. Significant outcome difference was found for two prosthetic valves. Balloon-expandable valve may effectively decrease the risk and degree of postoperative paravalvular leak, while self-expandable valve was conducive to lower stroke risk due to lower aortic stress. The numerical TAVR simulation process may become an assistant tool for prosthesis selection in pre-operative planning and postoperative prediction.

[Biomechanical Study of New Biodegradable Esophageal Stent].

The radial force of the degradable esophageal stent before and after degradation is one of the important indicators for effective treatment of esophageal stricture. Based on a combination of in vitro experiments and finite element analysis, this paper studies and verifies the biomechanical properties of a new type of degradable esophageal stent under different esophageal stricture conditions. Under radial extrusion conditions, the maximum stress at the port of the stent is 65.25 MPa, and the maximum strain is 1.98%; The peak values of stress and strain under local extrusion and plane extrusion conditions both appear in the extrusion area and the compression expansion area at both ends, which are respectively 48.68 MPa, 46.40 MPa, 0.49%, 1.13%. The maximum radial force of the undegraded stent was 11.22 N, and 97% and 51% of the maximum radial force were maintained after 3 months and 6 months of degradation, respectively. The research results verify the safety and effectiveness of the radial force of the new degradable esophageal stent, and provide a theoretical basis for the clinical treatment of esophageal stricture.

Sparstolonin B exerts beneficial effects on prostate cancer by acting on the reactive oxygen species-mediated PI3K/AKT pathway.

Prostate cancer is a major health concern in males worldwide, owing to its high incidence. Sparstolonin B (SsnB), a component of the Chinese herbal medicine Sparganium stoloniferum, is used to treat many diseases. However, the effects and mechanisms of action of SsnB in prostate cancer have not yet been reported. In this study, we evaluated the effects of SsnB on cellular processes and tumour growth. In particular, we verified that SsnB could inhibit the proliferation, migration and invasion of prostate cancer cells and induce apoptosis by activating G2/M phase arrest in vitro based on a series of cytological experiments. In vivo, we found that SsnB could inhibit tumour growth in nude mouse xenograft models. We further confirmed that SsnB could repress the PI3K/AKT pathway by increasing reactive oxygen species (ROS) accumulation and oxidative stress. Collectively, SsnB inhibits tumour growth and induces apoptosis in prostate cancer via the suppression of the ROS-mediated PI3K/AKT pathway and may be a new alternative to adjuvant therapy for prostate cancer.

Long-term survival and recurrence after curative resection for hepatocellular carcinoma in patients with chronic hepatitis C virus infection: a multicenter observational study from China.

BACKGROUND: Hepatocellular carcinoma (HCC) is a recognized sequalae of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. This study aimed to identify long-term survival and prognostic factors after curative resection for HCC among patients with chronic HCV infection. METHODS: From a Chinese multicenter database, the data of consecutive patients with HCV infection undergoing curative liver resection for initial HCC between 2006 and 2015 were retrospectively reviewed. Postoperative 30-day mortality and morbidity, long-term overall survival (OS) and recurrence-free survival (RFS) were evaluated. RESULTS: Among 382 HCC patients with HCV infection, 68 (18%) had concurrent HBV infection and 110 (29%) had portal hypertension. Postoperative 30-day morbidity and mortality rates were 45% and 2.9%, respectively. The 5-year OS and RFS rates were 45% and 34%, respectively. Multivariable Cox-regression analyses identified that concurrent HBV infection, presence of portal hypertension, largest tumor size > 5 cm, and macrovascular and microvascular invasion were independently associated with worse OS and RFS, while postoperative regular anti-HCV therapy was independently associated with better OS. CONCLUSION: Long-term prognosis after HCC resection among patients with HCV infection was worse in those with concurrent HBV infection and concomitant portal hypertension. Postoperative regular anti-HCV therapy was associated with better OS.

Antennal transcriptome analysis of the chemosensory gene families in Carposina sasakii (Lepidoptera: Carposinidae).

BACKGROUND: The peach fruit moth, Carposina sasakii Matsumura (Lepidoptera: Carposinidae), poses a serious threat to a variety of fruits and causes significant economic loss owing to difficulties in its prevention and control. The olfactory sense is generally acknowledged to be a novel target for pest control. However, a systematic study of the olfactory genes expressed in C. sasakii has not been reported yet. Here, we reported the antennal transcriptome of C. sasakii using high-throughput sequencing and annotated the main chemosensory multi-gene families. RESULTS: In the chemosensory gene families, 29 odorant-binding proteins, 13 chemosensory proteins, 1 sensory neuron membrane protein, 52 odorant receptors, 8 ionotropic receptors and 11 gustatory receptors were annotated in the C. sasakii antennal transcriptome. The number of olfactory genes obtained in our transcriptome was consistent with that identified in other lepidopteran insects, confirming that we basically accomplished the annotation of the chemosensory genes of C. sasakii in the adult antennal transcriptome. All sequences were annotated and analyzed by BLAST (basic local alignment search tool), and some chemosensory genes with specific functions were named according to the BLAST results and phylogenetic trees. Based on the expression profile in the transcriptome and phylogenetic analysis, differentially expressed genes (DEGs) were analyzed in both male and female adults. Finally, fluorescence quantitative real-time PCR was used to identify the male-specific or female-specific chemosensory genes that were putatively related to odor detection and recognition. Moreover, expression levels of OR33 and PBP2 were significantly higher in males than in females, indicating that these genes may interact with sex pheromones. We found some conserved antennal IRs and GRs involved in detecting sugar compounds (GR2, GR5, GR6, GR8) and carbon dioxide (GR1), which were also identified based on phylogenetic analysis. CONCLUSIONS: There are 114 putative chemosensory proteins expressed in C. sasakii identified in this study. The identification of these proteins will make the molecular mechanism of odor recognition accessible.

[Finite Element Analysis of Biodegradable Polylactic Acid Stent].

Biodegradable vascular stent, also known as the third generation stent, has recently been widely studied. Finite element models of three stents with the same structure and different specifications were developed. The mechanical behavior under crimping, expanding and fatigue testing were assessed by von Mises yield and Goodman convergence. The maximum stress during crimping, expanding and fatigue testing were all observed in the stent with the largest size. The results indicated that the largest stent had the highest risk of failure and also provided theoretical evidence for the worst case scenario in the fatigue testing.

Endoscopic Endonasal-Assisted Resection of Orbital Schwannoma.

Orbital schwannomas are rare and despite a variety of external surgical approaches previously utilized, removal of tumors located in the deep orbital apex remains challenging. The endoscopic endonasal approach has been used increasingly for various apical tumours, but few describe this technique for orbital schwannomas. The authors describe 2 cases of orbital schwannoma removed via an endoscopic endonasal assisted approach. The first patient was a 31-year-old Cantonese female who was found to have an 11 × 8 × 8 mm right orbital apical schwannoma which was removed using an endoscopic endonasal sphenoethmoidal approach. The second patient was a 78-year-old white male who had a 28 × 17 × 18 mm orbital schwannoma removed via a transcaruncular and endoscopic endonasal-assisted approach. These findings suggest that the use of an endonasal approach may facilitate the safe removal of selected medially located orbital schwannomas whose posterior margins involve the orbital apex.

Vessel Sampling and Blood Flow Velocity Distribution With Vessel Diameter for Characterizing the Human Bulbar Conjunctival Microvasculature.

PURPOSE: This study determined (1) how many vessels (i.e., the vessel sampling) are needed to reliably characterize the bulbar conjunctival microvasculature and (2) if characteristic information can be obtained from the distribution histogram of the blood flow velocity and vessel diameter. METHODS: Functional slitlamp biomicroscope was used to image hundreds of venules per subject. The bulbar conjunctiva in five healthy human subjects was imaged on six different locations in the temporal bulbar conjunctiva. The histograms of the diameter and velocity were plotted to examine whether the distribution was normal. Standard errors were calculated from the standard deviation and vessel sample size. The ratio of the standard error of the mean over the population mean was used to determine the sample size cutoff. The velocity was plotted as a function of the vessel diameter to display the distribution of the diameter and velocity. RESULTS: The results showed that the sampling size was approximately 15 vessels, which generated a standard error equivalent to 15% of the population mean from the total vessel population. The distributions of the diameter and velocity were not only unimodal, but also somewhat positively skewed and not normal. The blood flow velocity was related to the vessel diameter (r=0.23, P<0.05). CONCLUSIONS: This was the first study to determine the sampling size of the vessels and the distribution histogram of the blood flow velocity and vessel diameter, which may lead to a better understanding of the human microvascular system of the bulbar conjunctiva.

Endoscopic Transretracaruncular-Middle Meteas Tract for Insertion of a Porous Polyethylene-Coated Jones Tube.

PURPOSE: The purpose of this article is to describe a modified lacrimal bypass with a porous polyethylene-coated Jones tube. METHODS: A total of 180 patients (180 eyes) with a nonreconstructable lacrimal obstruction underwent lacrimal bypass with a porous polyethylene-coated Jones tube through a retrocaruncular-middle meatus tract approach with endoscopic assistance. All patients were followed up at least for 24 months. Success rate of lacrimal bypass was analyzed and complications were recorded. RESULTS: A total of 174 patients were finally included. Duration of surgery ranged from 28 to 47 minutes (mean 37.2 ±â€Š4.2 minutes). The mean duration of follow-up was 30.0 ±â€Š6.4 months (range 24-48 months). The mean tube length was 23.2 ±â€Š1.9 mm (range 20-28 mm). At the final review, complete success was achieved in 138 (79.3%) patients. Moderate success was achieved in 23 (13.2%) patients, and 13 (7.5%) patients failed. Of the 161 patients successfully treated, 24 patients underwent revision surgery to excise granulomas (15 patients) or adjust tube position (9 patients). The complications included granuloma proliferation around the openings of the tube (28 eyes), downward displacement of the tube (17 eyes), and ocular discomfort (15 eyes). The majority of downward tube migration occurred in patients who had a prior history of dacryocystorhinostomy. The treatment failed for 5 patients because of repeated granulomas covering the nasal tube openings, and the treatment failed for 8 patients because of downward displacement of the tube. CONCLUSIONS: Our procedure appears to be an effective method for closed insertion of a porous polyethylene-coated Jones.

[A Drug Delivery Device for Drug-eluting Stents Simulating the Cardiovascular Blood Flow Pattern].

A novel drug delivery device simulating the cardiovascular bloodfl ow pattern was introduced. The device was used to simulate the in vivo drug release in the drug-eluting stents. The results regarding the drug release rate were subject to the pattern from in vivo measurement. Therefore, the device was validated as a measurement method for in vivo drug release rate.

Measurement variability of the bulbar conjunctival microvasculature in healthy subjects using functional slit lamp biomicroscopy (FSLB).

The goal was to determine the variability of the quantitative measurement of the bulbar conjunctival microvascular morphology and hemodynamics by testing the repeatability and variation during office hours. Functional slit-lamp biomicroscopy (FSLB) was used to image the bulbar conjunctival microvasculature, including the vessel diameter, blood flow velocity/rate and fractal dimensions of the microvascular network. The temporal side of the bulbar conjunctiva in 20 healthy subjects was imaged. The subject was imaged at 9 AM to test the measurement repeatability by two independent graders. The intraclass correlation coefficient (ICC) and coefficient of repeatability (CoR) were calculated. These same subjects were then imaged every two hours from 9 AM to 5 PM to test the variation during office hours. Custom software was used to semi-automatically process all measurements. The CoR% and ICC values between two graders for measuring the vessel diameter were 4.87% and 0.989, respectively. For the axial blood flow velocity, the CoR% and ICC were 11.49% and 0.997, respectively. From 9 AM to 5 PM, there were no significant variations in the vessel diameter and hemodynamics (P>0.05), whereas the fractal dimensions of the non-invasive microvascular perfusion maps (nMPMs) were significantly increased at 3 PM and 5 PM compared with the baseline obtained at 9 AM (P<0.05). FSLB appears to be capable of measuring vessel diameter, blood flow velocity and fractal dimension of the microvascular network in the bulbar conjunctiva. Slight variations over office hours were observed in the microvascular network, while the blood flow velocity remained stable.

Slitlamp Photography and Videography With High Magnifications.

PURPOSE: To demonstrate the use of the slitlamp photography and videography with extremely high magnifications for visualizing structures of the anterior segment of the eye. METHODS: A Canon 60D digital camera with Movie Crop Function was adapted into a Nikon FS-2 slitlamp to capture still images and video clips of the structures of the anterior segment of the eye. Images obtained using the slitlamp were tested for spatial resolution. The cornea of human eyes was imaged with the slitlamp, and the structures were compared with the pictures captured using the ultra-high-resolution optical coherence tomography (UHR-OCT). The central thickness of the corneal epithelium and total cornea was obtained using the slitlamp, and the results were compared with the thickness obtained using UHR-OCT. RESULTS: High-quality ocular images and higher spatial resolutions were obtained using the slitlamp with extremely high magnifications and Movie Crop Function, rather than the traditional slitlamp. The structures and characteristics of the cornea, such as the normal epithelium, abnormal epithelium of corneal intraepithelial neoplasia, laser in situ keratomileusis interface, and contact lenses, were clearly visualized using this device. These features were confirmed by comparing the obtained images with those acquired using UHR-OCT. Moreover, the tear film debris on the ocular surface and the corneal nerve in the anterior corneal stroma were also visualized. The thicknesses of the corneal epithelium and total cornea were similar to that measured using UHR-OCT (P<0.05). CONCLUSIONS: We demonstrated that the slitlamp photography and videography with extremely high magnifications allow better visualization of the anterior segment structures of the eye, especially of the epithelium, when compared with the traditional slitlamp.