Electric Knife Research Articles

Efficacy and influencing factors of interventional bronchoscopy for the treatment of scarring airway stenosis: a multicenter retrospective investigation from China

Objectives: To evaluate the efficacy of interventional bronchoscopy for the treatment of scarring airway stenosis and to analyze the influencing factors related to the success rate. Methods: Between January 2013 to December 2016, 301 patients with scarring airway stenosis treated by interventional bronchoscopy in 18 tertiary hospitals were reviewed retrospectively. The methods of interventional bronchoscopy included electric knife cutting, laser cauterization, balloon dilation, cryotherapy, local drug usage and/or stenting. Airway stenosis characteristics and patients' performance status at baseline and after interventional bronchoscopy were recorded. The interval days between the first two interventional bronchoscopy treatment (maintained patency time) and the final treatment efficacy were recorded. Results: The clinical stability rate of interventional bronchoscopy for the treatment of scarring tracheal stenosis was 67.8% (204/301) . Stenosis sites (OR 1.548; 95% CI: 1.038-2.307, P=0.032) , dyspnea index (OR 2.140; 95% CI: 1.604-2.855, P<0.001) , and interventional method (OR 0.458; 95% CI: 0.267-0.787, P=0.005) were independent predictors associated with the efficacy of interventional bronchoscopy treatment. Stenosis sites (OR 1.508; 95% CI: 1.273-1.787, P<0.001) , stenosis grade (OR 1.581; 95% CI: 1.029-2.067, P=0.001) , anesthesia method (OR 1.581; 95% CI: 1.029-2.067, P<0.001) , and local drug usage (OR 1.304; 95% CI: 1.135-1.497, P<0.001) were independent predictors associated with the maintained patency time after first interventional bronchoscopy treatment. Conclusion: Interventional bronchoscopy is a useful treatment method for scarring airway stenosis. Enough attention should be paid to influencing factors in order to improve treatment efficacy during the treatment process.

Extraction of low horizontally and buccally impacted mandibular third molars by three-piece tooth sectioning.

The aim of this study was to investigate the clinical effect of the extraction of low horizontally impacted mandibular third molars by three-piece tooth sectioning. Sixty patients with low horizontally and buccally-impacted mandibular third molars on both sides were operated on under local anaesthesia. Three-piece tooth sectioning was used on one side (n=60) and the molars were extracted using a high-frequency electric knife, 45° reversed-angle high-speed turbine, and special long crank drill. Each molar was cut into three pieces, which were removed in the following order: middle, root, and crown. One month later, the molars on the other side of each patient's jaw were removed by conventional extraction (n=60) with the same equipment. The crown was cut and removed first, and then the remaining piece was extracted. The duration of the procedure, and incidence postoperative swelling, pain, and trismus were compared between the two groups. The procedure was shorter with the three-piece method (10.05 (0.51) min) than with the conventional method (20.15 (0.88) min, p<0.01). Postoperative swelling, pain, and trismus were all less severe with the three-piece method than with the conventional method (p<0.01). Three-piece tooth sectioning could be used to remove low horizontally and buccally-impacted mandibular third molars, as it can shorten the duration of the procedure, reduce trauma, and reduce the incidence of postoperative complications.

Investigating the influences of ventilation on the fate of particles generated by patient and medical staff in operating room

This study thoroughly investigated, using validated computational fluid dynamics (CFD) techniques, the influences of ventilation on the fate of particles generated by patient and medical staff in an operating room (OR) under a variety of operating conditions. The research first investigated that the body positions of surgeons (i.e., standing upright and bent over) have a significant impact on the spread of indoor pollutants. This can be one of the primary reasons that the conventional unidirectional ventilation system in the OR may still not mitigate the risk of surgical site infections (SSI). The study then revealed the adverse impacts of different upper respiratory tract characteristics of the patient (i.e., normal respiration, or coughing and sneezing under local/regional anesthesia) to the medical staff, disclosing the importance of wearing a respiratory mask of such patients during the surgery. This study further explored the influences of smoke particles generated from the patient's wound to the medical staff when using an electric knife during the surgery under four different ventilation methods, including the conventional unidirectional ventilation and three localized ventilation approaches proposed by this research. The results indicate that localized ventilation can be an effective supplement to the central ventilation system to mitigate the potential cross-infection risks between patient and medical staff.

Sa1321 VALUE OF ENDOSCOPY ULTRASONOGRAPHY IN THE TREATMENT OF DIFFUSE ESOPHAGEAL SPASM WITH PERORAL ENDOSCOPIC MYOTOMY

Diffuse esophageal spasm (DES) is a rare esophageal motility disorder of normal amplitude and accompanied by dysphagia. It is characterized by simultaneous, uncoordinated or rapidly propagated contractions. The etiology of DES is unknown. There are various theories proposed. Muscular hypertrophy or hyperplasia is present in the distal part of the esophagus comprising almost two-thirds of the esophagus in DES. High-resolution manometry (HRM) and esophageal pressure topography (EPT) is valuable for the diagnosis .These also be used to determine the length of myotomy preoperatively which is not very exact. Now, extended myotomy of the esophageal body or peroral endoscopic myotomy(POEM) is accepted to treat DES. How to determine the entire length of myotomy is important which needs including all the affected segment and extend several centimeters superior to the proximal border of the spastic region to prevent remnants of spasticity. Using high resolution 20 MHz small ultrasonic probe to detect the thickness of esophageal muscle layer from the upper and lower parts of the obvious spasm ring under endoscope. Recording the beginning position and region where the thickness of myometrium thickening. The thickness is obviously thicker than normal esophageal. The length of thickening region is different. The length of myotomy is determined preoperatively with ultrosound. Using a electric knife to cut the circular muscle from the begining of thickness to 2 centimeters below the cardia. The thickness of muscle layer is segmental thickening while common esopheal only 3 millimeters,The length of myotomy is different from 10 to 17centimeters. So,Using endoscopy ultrasonography to judge both the initial position and length of myotomy is valuable. And this can accelerate the accuracy of POEM procedure.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Qualitative analysis of surgical smoke produced during burn operations.

Burned tissue is necrotic and it is surrounded by a zone of stasis and hyperaemia with changed cell metabolism. The removal of burned tissue using an electric knife releases large amounts of surgical smoke. The aim of the research was to analyse volatile, nonpolar, organic compounds that are released during the excision of burned tissue using an electric knife (mono- and bipolar). The study includes analysis from 40 solid-phase microextraction (SPME) fibres, exposed during 10 interventions (6 escharotomy and 4 necrectomy). The analysis of volatile compounds was performed using mass spectrometry gas chromatography (GCxGC-ToFMS).The total analysis covered 432 compounds, whereas after the removal of the "background" compounds - 153 volatile organic substances remained. The analysis of surgical smoke showed that, including derivatives, benzene constituted as much as 17.65% of all of the studied compounds. Cyclic compounds constituted on average 22.5% of the analysed substances, out of which cycloheptatrien constituted 20.26%. Alkanes, alcohols and their derivatives constituted nearly 25% of volatile organic compounds, with chloromethane constituting as much as 13.7%. Permutational multivariate analysis of variance (PERMANOVA) revealed statistically significant differences between escharotomy and necrectomy patients (F(1.9) = 5.91, p = 0.007).Our study revealed the presence of complex toxic hydrocarbon derivatives in surgical smoke. We also observed that the content of surgical smoke is different depending on the type of the conducted intervention. So far, no studies focusing on hazards posed by surgical smoke that is released during the resection of burned tissue are in the literature.

Application of meticulous anatomy skills with straight bipolar electric coagulation forceps in thyroid surgery

Objective: To compare the efficacies of the two techniques of "micro-hemostasis and micro-cutting" with straight bipolar electrocoagulation forceps and traditional clamp-ligation for hemostasia in thyroid surgery. Methods: A total of 228 patients who underwent surgical treatment for thyroid neoplasms in our hospital between January 2015 and December 2018 were retrospectively analyzed, including 50 males and 178 females, aged 23-68 years old. Of those, 150 cases as electric knife group received traditional thyroid surgery between January 2015 and December 2018 and 78 cases as bipolar electrocoagulation group received thyroid surgery by using the technique of bipolar electrocoagulation with meticulous anatomy between January 2018 and December 2018. The total operation time, single operation time, intraoperative hemorrhage, postoperative drainage volume on the first day, postoperative hoarseness and hypocalcemia were compared between the two groups. SPSS 16.0 was used to analyze the data. Results: The total operation time and intraoperative hemorrhage in the bipolar electrocoagulation group were significantly lower than those in the electric knife group ((59.33±18.29)min vs (77.21±25.39)min, (14.83±9.22)ml vs (36.86±11.80)ml, all P<0.01). The single operation time of the bipolar electrocoagulation group was shorter than that of the electric knife group((10.25±6.16) min vs (20.34±7.24)min, (16.25±7.15)min vs (35.68±8.25)min, (12.12±5.25)min vs (20.68±7.26)min, t value was 3.948,16.262,8.238, all P<0.01).There was no significant difference between the two groups in postoperative drainage volume on the first day (P>0.05) and the incidence of postoperative hoarseness (P>0.05), while the incidence of hypocalcemia in the bipolar electrocoagulation group(10.26%) was lower than that in the electric knife group(21.33%,χ(2)=4.353, P<0.05). Conclusions: The fine dissection for thyroid operation can be achieved by using straight bipolar electrocoagulation tweezers. The use of "micro-hemostasis" and "micro-cutting" technique with bipolar electrocoagulation tweezers can greatly reduce intraoperative bleeding, operation time and postoperative complication.

Study on Influencing Factors and Control Strategies of Surgical Smoke Concentration Distribution

Paroxysmal fumes during surgical operations endanger the health of medical staff. Special measures for removing surgical smoke are lacking. Article Real-time monitoring of particulate matter concentrations in surgical smoke at different locations under different surgical conditions were explored, and a particulate matter purification control strategy was proposed. The PM2.5 and PM10 concentrations in the operating and respiratory zones near the operating table were about 3.0 times more than the specified value, but both surgical procedures met the requirements of PM concentration in the public zone. Therefore, a clean operating room is not clean for medical staff. The smoke produced by the three scalpels resulted in particle sizes of 0.30 - 2.50 μm in the respiratory zone, and calculate apparent density of powders to be 1.21g cm-3. The surgical smoke produced by the ultrasound scalpel resulted in the highest median PM10 concentration in the operating area. The results show that the smoke produced by different surgical conditions is mainly ultra-fine particles, which are more likely to harm the health of medical staff. A small surgical smoke circulation purification and dust removal system was designed, which could effectively suppress the spread of surgical smoke and reduce the occupational hazards of medical staff. The optimized control plan could significantly reduce the PM2.5 concentration value at measurement point a when the electric knife was turned on by approximately 200.0 %. The PM2.5 concentration of breathing zone was close to 75.0 μg m-3, which basically met the occupational health requirements. The decrease in the PM2.5 concentration of operating zone was about 50.0 %, but it still exceeded the limit. It had a reference value for the occupational health protection of the first-line medical staff of existing epidemics.

Tu1940 VISUALIZATION AND CLASSIFICATION OF GASTRIC SUBEPITHELIAL LESIONS ON SUBMUCOSAL ENDOSCOPY: A PROSPECTIVE INVESTIGATION

Several mucosal incision biopsy methods (MIBs) using an electric knife have recently been placed as a secondary option of the standard method, EUS-FNA, in the gastrointestinal subepithelial lesions (SELs) sampling. As one of them, we developed submucosal tunneling biopsy (STB)1 which could identify and sample tumors under direct vision through the submucosal tunnel. The diagnostic ability of MIBs depends on visualization of the tumor itself. Accordingly, the clinical significance regarding classification of endoscopically visualized feature (EVF) 2, which each tumor itself expresses color, shape and solidity, should be clarified.

Analysis of the changes of PM10 concentration in surgical smoke

Objective To investigate the changes of inhalable particulate matter (PM10) concentration in operating room and its influencing factors under different surgical methods and procedures. Methods From June to August 2016, 23 cases of open surgery and 10 cases of laparoscopic surgery in a hospital were selected by convenience sampling method. The change of PM10 concentration during operation was monitored by P-5 digital dust meter. The measuring position was in the area of laminar air supply ceiling device (the position of the surgeon's mouth and nose is equal, and the vertical distance above the incision is 50 cm) or outside the area of the laminar air supply ceiling device (working area of itinerant nurses) . The effects of different surgical methods (open surgery and endoscopic surgery) and surgical procedures (patient admission, disinfection of skin, exposure of surgical field, tissue separation, incision closure and end of operation) on the concentration of PM10 were recorded and analyzed. Results The concentration of PM10 in 33 surgeries with different surgical procedures met the national ambient air quality standards. The average PM10 concentration of the 6 surgical procedures was (14.21±3.86) μg/m3. Comparing between open surgery and laparoscopic surgery, there were significant differences in PM10 concentration between the two groups in terms of admission, disinfection of skin, field exposure, tissue separation, incision closure and end of operation (U/t=-4.45, 10.37, 7.52, 4.90, 8.08, -4.39; P<0.05) . There were significant differences in PM10 concentration in patients whether to use high frequency electric knife or not in terms of admission, disinfection of skin, field exposure, tissue separation, incision closure and end of operation (U/t=-4.51, 7.22, 6.96, 5.24, 8.60, -4.36; P<0.05) . Conclusions The concentration of PM10 in the whole surgical process complies with national standards. The change of PM10 concentration during surgery is related to different surgical methods and the use of high frequency electric knife. Key words: Surgical procedures, operative; Smog; PM10; Concentration; Air quality; Operative method; Operative procedure; High frequency electric knife

The cervical function and pregnancy outcomes after hysteroscopic resection of the complete uterine septum, duplicate cervix and vaginal septum

ObjectiveTo evaluate cervical function and pregnancy outcomes after hysteroscopic resection of the complete uterine septum, duplicate cervix and vaginal septum with Metzenbaum scissors. MethodsBetween January 2010 and December 2016, 13 patients admitted to the Department of Obstetrics and Gynecology of Sir Run Run Shaw Hospital with complete uterine septum, duplicate cervix and vaginal septum, were enrolled into this study. The cervical and corporal septum was cut by Metzenbaum scissors, and residual septum was cut by micro scissors under hysteroscopy. The vaginal septum was cut with the unipolar electric knife. ResultsThe operation time was about 10 ± 1.31 min. All the 13 patients present normal uterine cavities without scar formation under hysteroscopy at 3 months after operation, there was mild adhesions between anterior and posterior intrauterine wall on 2 cases. After operation, there were 13 pregnancies naturally conceived in 11 patients, 10 deliveries. The live birth rate was 76.92%, the early miscarriage rate was 23.08%. The cesarean section rate was 30%, the vaginal delivery rate was 70%, and all were term births. ConclusionThe operation was simple, convenient, and fast, without any complications and cervical insufficiency. It was easy to have vaginal deliveries.

Feasibility Study of a Newly Developed Hybrid Energy Device Used During Laparoscopic Liver Resection in a Porcine Model.

Although various devices have been clinically used for laparoscopic liver resection (LLR), the best device for liver parenchymal transection remains unknown. Olympus Corp (Tokyo, Japan) developed a laparoscopic hybrid pencil (LHP) device, which is the first electric knife to combine ultrasound and electric energy with a monopolar output. We aimed to evaluate the feasibility of using the LHP device and to compare it with the laparoscopic monopolar pencil (LMP) and laparoscopic ultrasonic shears (LUS) devices for LLR in a porcine model. Nine male piglets underwent laparoscopic liver lobe transections using each device. The operative parameters were evaluated in the 3 groups (n = 24 lobes) during the acute study period. The imaging findings from contrast-enhanced computed tomography and histopathological findings of autopsy on postoperative day 7 were compared among groups (n = 6 piglets) during the long-term study. The transection time was shorter ( P = .001); there was less blood loss ( P = .018); and tip cleaning ( P < .001) and instrument changes were less often required ( P < .001) in the LHP group than in the LMP group. The LHP group had fewer instances of bleeding ( P < .001) and coagulator usage ( P < .001) than did the LUS group. In the long-term study, no postoperative adverse events occurred in the 3 groups. The thermal spread and depth of the LHP device were equivalent to those of the LMP and LUS devices (vs LMP: P = .226 and .159; vs LUS: P = 1.000 and .574). The LHP device may be an efficient device for LLR if it can be applied to human surgery.

RA01.05: MINIMALLY INVASIVE ESOPHAGECTOMY AND 3-FIELD LYMPH NODE DISSECTION (ESOPHAGEAL SUSPENSION METHOD)—FUJIAN MEDICAL UNIVERSITY UNION HOSPITAL EXPERIENCE

Abstract Description We have modified our procedures of lymphadenectomy, with the purpose of radical lymph node dissection, because we believe that radical lymph node dissection along bilateral RLNs may be crucial for post-operative accurate staging, local control and better prognosis. Programmed lymphadenectomy includes several steps. Programmed extensive lymphadenectomy along right RLN included 3 steps: (1) Location of the right vagus nerve. (2) Loaction of the root of the right RLN. (3) Extensive lymphadenectomy. Programmed extensive lymphadenectomy along left RLN was conducted subsequently, which included 4 steps. (1) Esophageal suspension. (2) Lymph node rolling.(3) Location and identification of left RLN. (4) Extensive lymphadenectomy. During the whole procedure, we preferred to use blunt separation in the zones near the RLN, and preferred to use the ultrasound knife and scissors rather than electrical knife. The thoracic esophagus was not cut off during the procedure. After the thoracic procedures, we do the laparoscopic gastric dissociation and lymph node dissection. When metastasis to either RLN chains was confirmed by routine intra-operative frozen section, bilateral cervical lymphadenectomy was also performed. We divided the procedures into steps, which could have following advantages: more radical lymph node clearance with skeletonization of the nerves, reduced injuries due to definite location and identification of the nerves, more easier for surgeons to expose the surgical field and more easier for new-hands to master the procedures. Minimally invasive esophageactomy and thoracoscopic programmed extensive lymphadenectomy along the left and right RLNs in esophagectomy was feasible and safe. According to our study, programmed extensive lymphadenectomy yielded sufficient lymph nodes, with acceptable postoperative complications. Disclosure All authors have declared no conflicts of interest.

Kebab: can the traditional cooking process sanitize a natural contamination by Listeria monocytogenes?

Over the last few years a considerable spread of ethnic foods was observed in Italy. Among them is the Döner kebab. During 2014-2015, in order to evaluate the effectiveness of traditional cooking process, raw product (defrosted), sliced cooked portions cut through electric knife and assembled sandwich were officially sampled in kebab houses and in a local industrial kebab producer in Reggio Emilia (a province in Italy). Microbiological researches for safety and hygienic microbiological indicators were carried out (research of Salmonella, Listeria monocytogenes, Campylobacter and Shiga toxin-producing Escherichia coli; enumeration mesophilic aerobic bacteria, lactic acid bacteria, sulfite-reducing bacteria growing under anaerobic conditions, yeasts and molds). Between the raw and the cooked product an average of 3 log reduction in mesophilic aerobic bacteria counts was observed. In two out of three kebab houses sampled, which were supplied by the same local industrial producer, the presence of L. monocytogenes was detected. During the official inspection carried out at the production plant a contamination of L. monocytogenes was assessed in both ambient and instruments. Furthermore, 3 lots of products were analyzed and all were found to be contaminated by L. monocytogenes (always above 100 CFU/g). In order to verify the capability of the traditional cooking process to reduce the risk of contamination at an acceptable level, a batch of naturally contaminated kebab (4.5 log CFU/g) was cooked and sliced simulating a day work activity in a kebab shop. The product was then sampled during preparation and enumeration of L. monocytogenes was obtained. After an hour of cooking, the residual contamination was 1.8 log CFU/g, after two hours and a half L. monocytogenes was no longer detectable in the product, but half an hour later it was again detectable in 25g. At the end of the experiment, the contamination grown up to the same level enumerated after an hour of cooking (1.8 log CFU/g). Considering the microbiological results, traditional cooking obtained a rate of -2.40 log CFU/gh-1, a D=26 min that corresponds to a temperature of maximum 60°C (z=6). In conclusion, our experiment demonstrates the traditional kebab cooking process could not always guarantee a complete product decontamination.

Particular Chromosomal Distribution of Microsatellites in Five Species of the Genus Gymnotus (Teleostei, Gymnotiformes).

Microsatellites show great abundance in eukaryotic genomes, although distinct chromosomal distribution patterns might be observed, from small dispersed signals to strong clustered motifs. In Neotropical fishes, the chromosome mapping of distinct microsatellites was employed several times to uncover the origin and evolution of sex and supernumerary chromosomes, whereas a detailed comparative analysis considering different motifs at the chromosomal level is scarce. Here, we report the chromosomal location of several simple sequence repeats (SSRs) in distinct electric knife fishes showing variable diploid chromosome numbers to unveil the structural organization of several microsatellite motifs in distinct Gymnotus species. Our results showed that some SSRs are scattered throughout the genomes, whereas others are particularly clustered displaying intense genomic compartmentalization. Interestingly, the motifs CA, GA, and GAG exhibited a band-like pattern of hybridization, useful for the identification of homologous chromosomes. Finally, the colocalization of SSRs with multigene families is probably related to the association of microsatellites with gene spacers in this case.

Comparison of efficacy and safety between thulium laser and high frequency electric knife on peroral endoscopic myotomy

Objective To evaluate the efficacy and safety of 1 940 nm thulium laser on peroral endoscopic myotomy (POEM) for treatment of patients with achalasia of cardia. Methods Fifteen patients undergoing POEM in Beijing Friendship Hospital from February 2016 to November 2016 were enrolled and divided into 1 940 nm thulium laser group (n=7) and high frequency electric knife group (n=8) using zelen′s design, with followed-up for three months. The operation time, success rate, efficacy, and complications were compared between the two groups. Results All the procedures were successfully completed. There was no significant difference on baseline between the two groups (P>0.05). The time of total operation, creating submucosal tunnel, myotomy, and closing incision were not significantly different between the two groups (all P>0.05). The bleeding amount, creating tunnel bleeding amount, and myotomy bleeding amount were not significantly different between the two groups (all P>0.05). The complication rate during operation and one week after operation was not significantly different between the two groups (P=0.76). The time of creating mucosal incision for the 1 940 nm thulium laser group was longer than that of the high frequency electric knife group(3.7±3.0 min VS 2.3±1.3 min, P=0.02). After one month of follow-up, the efficiency of the 1 940 nm thulium laser group and the high frequency electric knife group was 100.0% (7/7) and 87.5% (7/8), respectively (P=0.33), and the complication rate was 14.3% (1/7) and 12.5% (1/8), respectively (P=0.92). After three months of follow-up, the efficiency of the two groups was 100.0% (7/7) and 75.0% (6/8), respectively (P=0.16), and the complication rate was 28.6% (2/7) and 12.5% (1/8), respectively (P=0.60). Conclusion 1 940 nm thulium laser and high frequency electric knife both have good utility on POEM. 1 940 nm thulium laser decreases the operating time and bleeding compared with high frequency electric knife. Key words: Laser; High frequency electric knife; Achalasia; Peroral endoscopic myotomy

Simple Technique for Reducing the Buccal Fat Pad During Mandibular Orthognathic Surgery.

Sagittal split ramus osteotomy and intraoral vertical ramus osteotomy are commonly performed for the correction of jaw deformities. However, during mandibular orthognathic surgeries such as sagittal split ramus osteotomy and intraoral vertical ramus osteotomy , the authors sometimes encounter exposure of the buccal fat pad (BFP), which decreases the surgical field. The exposed BFP makes it difficult to perform these operations, may result in unexpected complications, and may increase the operation time. Therefore, the authors herein describe a simple, safe, and convenient technique for reducing the volume of the exposed BFP during mandibular orthognathic surgery using an electric knife in the coagulation mode.

Massive hard palate tumor removed with an electric knife

Massive hard palate tumor removed with an electric knife

Shape design sensitivity and optimization of anisotropic functionally graded smart structures using bicubic B-splines DRBEM

A new shape optimization technique is developed, using bicubic B-splines dual reciprocity boundary element method, for anisotropic functionally graded smart structures to minimize weight while satisfying certain constraints upon stresses and geometry. An implicit differentiation of the boundary integral equation with respect to geometric design variables is used to calculate shape design sensitivities of anisotropic materials. This method allows the coupling of an optimizing technique and a boundary element elastic stress analyzer to form an optimum shape design algorithm in two dimensions and also allows high-accuracy computation. The boundary element method needs much fewer data related only to the considered boundary of the structure, so it is very suitable for shape optimization in comparison with the finite element method.Because of the non-linear behavior of weight and stresses, the numerical optimization method used in the program is the feasible direction approach, together with the one-dimensional golden-section search technique. The two-dimensional electric fillet knife used as the numerical example in order to verify the formulation and the implementation of the proposed method.

Anti-adhesive Property of Maize Leaf Surface Related with Temperature and Humidity

The anti-adhesive surfaces have always aroused great interest of worldwide scientists and engineers. But in practical applications, it often faces the threat and impact of temperature and humidity. In this work, the excellent anti-adhesive performance of maize leaf under high temperature and humidity were investigated in detail. Firstly, the adhesion forces of the maize leaf surface under different temperature and humidity were measured by using Atomic Force Microscopy (AFM). The temperature of the substrate was varied between 23 °C to 100 °C, and the ambient relative humidity is from 18% to 100%. It was found that the adhesion force of maize leaf decreased with the increase of temperature and humidity. The mechanism of its excellent anti-adhesive performance of maize leaf under high temperature and relative humidity was revealed. The transverse and longitudinal ridges on maize leaf surface interlace with each other, forming small air pockets, which reduces the actual contact area between the object and the maize leaf. With the increase of humidity, the liquid film will be formed in the air pockets gradually and so much water vapor is produced with increase of temperature. Then the air flow rate increases though the wavy top of transverse ridges, inducing the dramatic decrease of adhesion force. Inspired by this mechanism, four samples with this bionic structure were made. This functional “biomimetic structure” would have potential value in the wide medical equipments such as high frequency electric knife with anti-adhesion surface under high temperature and high humidity.

Large sialolith of the duct of submandibular salivary gland removed with electric knife

Large sialolith of the duct of submandibular salivary gland removed with electric knife