Research status and progress on limb preservation technology / 器官移植

Limb replantation and transplantation is the optimal treatment for traumatic limb amputation. Safe and effective limb preservation is the key factor to determine the success of limb replantation and transplantation. Currently, static cold storage is the gold standard of limb preservation. However, the preservation time is short, which may no longer meet clinical requirements. With rapid development of organ preservation in recent years, novel preservation technologies, such as ultra-low temperature preservation, supercooling preservation and mechanical perfusion preservation, have successively emerged. However, at present, these techniques are primarily applied to the preservation of solid organs rather than composite tissue allografts with blood vessels including limbs. In this article, research status and progress on the application of static cold storage and mechanical perfusion preservation in limb preservation were reviewed, aiming to provide reference for clinical application of limb preservation technology and promote the development of limb replantation and transplantation.

Research on a portable shielding-free ultra-low field magnetic resonance imaging system / 生物医学工程学杂志

The portable light-weight magnetic resonance imaging system can be deployed in special occasions such as Intensive Care Unit (ICU) and ambulances, making it possible to implement bedside monitoring imaging systems, mobile stroke units and magnetic resonance platforms in remote areas. Compared with medium and high field imaging systems, ultra-low-field magnetic resonance imaging equipment utilizes light-weight permanent magnets, which are compact and easy to move. However, the image quality is highly susceptible to external electromagnetic interference without a shielded room and there are still many key technical problems in hardware design to be solved. In this paper, the system hardware design and environmental electromagnetic interference elimination algorithm were studied. Consequently, some research results were obtained and a prototype of portable shielding-free 50 mT magnetic resonance imaging system was built. The light-weight magnet and its uniformity, coil system and noise elimination algorithm and human brain imaging were verified. Finally, high-quality images of the healthy human brain were obtained. The results of this study would provide reference for the development and application of ultra-low-field magnetic resonance imaging technology.

Risk factors of red blood cell infusion in very low/ultra-low birth weight neonates with respiratory distress syndrome / 中国输血杂志

【Objective】 To investigate the risk factors of red blood cell transfusion frequency (fRBCT) toward newborns with very/extremely low birth weight (V/ELBW) who experienced 57 days, >2.75 days and >23.75 days. 【Conclusion】 Increased fRBCT may complicate V/ELBW NRDS newborns who experienced <32 weeks of gestational age with NEC, hematosepsis, BPD and ROP. Duration of hospital stay, invasive ventilation and IVN are relatively effective predictive indicators for whether such cases have undergone ≥3 red blood cell transfusions throughout their hospitalization.

Sphincter preservation operation and comprehensive treatment for ultra-low rectal cancer / 中华消化外科杂志

In the past 20 years, the multidisciplinary treatment model based on evidence-based medicine has significantly increased the rate of sphincter-preservation operation for rectal cancer. How to preserve rectum and anal function, avoid permanent colostomy, and improve post-operative quality of life of patients while ensuring radical resection of tumor, remains to be a key and hot topic in surgical treatment of rectal cancer. Based on literatures and clinical experiences, the authors summarize issues of sphincter preservation operation and comprehensive treatment, including intersphincteric resection, conformal sphincter preservation operation, total neoadjuvant therapy and radioimmunotherapy, for ultra-low rectal cancer, in order to provide reference for the colleagues.

Ultra-low CONtraSt PCI vs conVEntional PCI in patients of ACS with increased risk of CI-AKI (CONSaVE-AKI)

Objectives: This prospective, randomized study assessed short-term outcomes and safety of ultra-low contrast percutaneous coronary intervention(ULC-PCI) vs conventional PCI in high risk for contrast induced acute kidney injury(CI-AKI) patients presenting with acute coronary syndrome(ACS). Background: Patients at an increased risk of developing CI-AKI can be identified prior to PCI based on their pre-procedural risk scores. ULC-PCI is a novel contrast conservation strategy in such high risk patients for prevention of CI-AKI. Methods: 82 patients undergoing PCI for ACS were enrolled having estimated glomerular filtration rate(eGFR) < 60 ml/min/1.73 m2 and moderate to very high pre-procedural risk of developing CI-AKI as calculated by Maioli risk calculator. They were randomized into two groups of 41 patients each of ULCPCI (contrast volume patient's eGFR) and conventional PCI (contrast volume 3xpatient's eGFR). Primary end point was development of CI-AKI. Results: Baseline clinical and angiographic characteristics were similar between groups. Primary outcome of CI-AKI occurred more in patients of the conventional PCI group [7 (17.1%)] than in the ULC PCI group [(0 patients), p ¼ 0.012]. Contrast volume (41.02 (±9.8) ml vs 112.54 (±25.18) ml; P < 0.0001) was markedly lower in the ULC-PCI group. No significant difference in secondary safety outcomes between two study arms at 30 days. IVUS was used in 17% patients in ULC PCI. Conclusion: ULC-PCI in patients with increased risk of developing CI-AKI is feasible, appears safe, and has the potential to decrease the incidence of CI-AKI specially in resource limited setting such as ours where coronary imaging by IVUS is not possible in every patient.

The principles of ultra-low contrast percutaneous coronary intervention

Ultra-low contrast percutaneous coronary intervention (ULCPCI) can be performed electively in advanced chronic kidney disease. Engage guide catheter and advance guidewire into the coronary artery without using contrast. IVUS-guided PCI can reduce the contrast load. Perform co-registration of distal and proximal radio-opaque marker bands of intravascular ultrasound (IVUS) catheter. Deploy the stent at the target lesion under fluoroscopic guidance of these co-registered position of the IVUS-marking images. Complete the ULCPCI procedure with a final angiography using minimal contrast. Newer contrast sparing techniques and intravascular imaging technologies provide opportunities to perform ULCPCI efficiently with good results and the least complications

Reassessment of intersphincteric resection in the sphincter-preserving operation for ultra-low rectal cancer / 中华胃肠外科杂志

Intersphincteric resection (ISR), as an ultra-low sphincter-preserving operation, is widely used in clinical practice at present. ISR can allow some patients with very low rectal cancer to avoid the pain of anal resection while ensuring oncological efficacy. However, the procedure of ISR requires wider intersphincteric dissection which may cause nerve damage, and the removal of partial or total internal anal sphincter as an "inherent defect" of ISR can result in poor anal function postoperatively. Based on the in-depth understanding of regional anatomy and physiological function, the author proposed a new functional sphincter preservation operation for very low rectal cancer-conformal sphincter preservation operation (CSPO) which has achieved good outcome in clinical practice. This article will revisit the brief history of rectal cancer surgery and discuss the main mechanisms underlining the poor anal function after ISR. Based on the anatomical study of the pelvic floor and anal canal, CSPO can improve the postoperative anal function of very low rectal cancer patients by reducing the damage of the autonomic nerves, receptor corpuscles and muscle fibers in the intersphincteric space, retaining more dentate line and internal sphincter with the design of resection line of tumor lower border under direct vision, and elevating the anastomosis height. At the same time, the future treatment prospect of low rectal cancer is envisioned.

Clinical efficacy of laparoscopic modified Parks operation on the ultra-low rectal cancer / 中南大学学报(医学版)

OBJECTIVES@#To investigate the clinical efficacy of laparoscopic modified Parks operation on the patients with ultra-low rectal cancer.@*METHODS@#According to the preoperative stage and intraoperative anastomotic position, 98 patients with ultra-low rectal cancer above T2 stage underwent laparoscopic Dixon operation, modified Parks operation and Miles operation, respectively. All patients were divided into 3 groups: a Dixon operation group (@*RESULTS@#The patients were more obese, the distance between tumor and anal margin was closer, and the operation time was longer in the modified Parks operation group than those in the Dixon operation group (all @*CONCLUSIONS@#Laparoscopic modified Parks operation is a safe, economical and effective anus preservation operation, which can not only save the anus for some patients who had to perform Miles operation, but also recover better and faster after operation. Although the early anal function of patients performed with the modified operation is poor, it can gradually recover to the same level as the patients performed with the Dixon operation.

Ultra-low-dose chest computed tomography without anesthesia in the assessment of pediatric pulmonary diseases / Tomografia computadorizada de tórax de ultrabaixa dosagem sem anestesia naavaliação de doenças pulmonares pediátricas

Abstract Objective To evaluate the feasibility of using ultra-low-dose computed tomography of the chest with iterative reconstruction without anesthesia for assessment of pulmonary diseases in children. Methods This prospective study enrolled 86 consecutive pediatric patients (ranging from 1 month to 18 years) that underwent ultra-low-dose computed tomography due to suspicion of pulmonary diseases, without anesthesia and contrast. Parameters used were: 80 kVp; 15-30 mA; acquisition time, 0.5 s; and pitch, 1.375. The adaptive statistical iterative reconstruction technique was used. Subjective visual evaluation and quantitative assessment of image quality were done using a 5-point scale in 12 different structures of the chest. Results Mean age was 66 months (interquartile range, 16-147). Final diagnosis was performed in all exams, and 44 (51.2%) were diagnosed with cystic fibrosis, 27 (31.4%) with bronchiolitis obliterans, and 15 (17.4%) with congenital pulmonary airways malformations. Diagnostic quality was achieved in 98.9%, of which 82.6% were considered excellent and 16.3% were slightly blurred but did not interfere with image evaluation. Only one case (1.2%) presented moderate blurring that slightly compromised the image, and previous examinations demonstrated findings compatible with bronchiolitis obliterans. Mean effective radiation dose was 0.39 ± 0.15 mSv. Percentages of images with motion artifacts were 0.3% for cystic fibrosis, 1.3% for bronchiolitis obliterans, and 1.1% for congenital pulmonary airways malformations. Conclusion Chest ultra-low-dose computed tomography without sedation or anesthesia delivering a sub-millisievert dose can provide image quality to allow identification of common pulmonary anatomy and diseases.

Resumo Objetivo Avaliar a viabilidade do uso de tomografia computadorizada com ultrabaixa dose com reconstrução iterativa sem anestesia para avaliação de doenças pulmonares em crianças. Métodos Este estudo prospectivo envolveu 86 pacientes pediátricos consecutivos (um mês a 18 anos) submetidos à tomografia computadorizada com ultrabaixa dose por suspeita de doenças pulmonares, sem anestesia e contraste. Os parâmetros utilizados foram: 80 kVp; 15-30 mA; tempo de aquisição, 0,5 s; e pitch de 1,375. Foi utilizada a técnica de reconstrução estatística adaptativa iterativa. A avaliação visual subjetiva e a avaliação quantitativa da qualidade da imagem foram feitas com uma escala de 5 pontos em 12 estruturas do tórax. Resultados A média de idade foi de 66 meses (intervalo interquartil, 16-147). O diagnóstico final foi feito em todos os exames e 44 (51,2%) foram diagnosticados com fibrose cística, 27 (31,4%) com bronquiolite obliterante e 15 (17,4%) com malformação congênita pulmonar das vias aéreas. A qualidade diagnóstica foi alcançada em 98,9% dos casos, dos quais 82,6% foram considerados excelentes e 16,3% alteração leve na definição, mas isso não interferiu na avaliação da imagem. Apenas um caso (1,2%) apresentou alteração moderada na definição, comprometeu discretamente a imagem, e exames prévios demonstraram achados compatíveis com bronquiolite obliterante. A dose de radiação média efetiva foi de 0,39 ± 0,15 mSv. As porcentagens de imagens com artefatos de movimento foram de 0,3% para fibrose cística, 1,3% para bronquiolite obliterante e 1,1% para malformação congênita pulmonar das vias aéreas. Conclusão É possível realizar a tomografia computadorizada com ultrabaixa dose torácica sem sedação ou anestesia, administrando uma dose de submilisievert, com qualidade de imagem suficiente para a identificação pulmonar anatômica e de doenças pulmonares comuns.

Development of a Wearable Wireless ECG Monitoring System with Ultra-low Power Consumption / 中国医疗器械杂志

This study describes the development of a wireless and wearable ECG monitoring system with ultra-low power consumption. The system is mainly composed of a connection part of an ECG electrode sticker, an electrocardiogram collecting part, a data storage part, a Bluetooth main control unit, a charging module, a voltage regulator and a lithium battery. The low-power ECG acquisition chip ADS1292R and the ultra-low-power Bluetooth microcontroller nRF51822 together constitute the ECG signal acquisition and wireless data communication part. The collected ECG signals can be sent to the mobile APP through the Bluetooth function provided by the MCU, and can completly display and analysis to achieve low power system. After testing, the system power consumption is only (3.7 V×2.87 mA)10.619 mW, and if it is optimized, it can further reduce power consumption, therefore, the system design can have good applicability.

A prospective study of contrast preservation using ultra-low contrast delivery technique versus standard automated contrast injector system in coronary procedures

Background We aimed to assess the decrease in contrast media volume (CMV) with ultra-low contrast delivery technique (ULCD) developed at our institution versus the usual automated contrast injector system (ACIS) contrast delivery in coronary procedures. Methods We analyzed the amount of contrast given in the consecutive 204 patients of the operators who use ULCD technique versus consecutive 200 patients of the other operators who use ACIS without ULCD technique for coronary angiograms and/or percutaneous coronary interventions (PCIs) from May 2017 to July 2018 at our center. We calculated the mean CMV between these groups. Results We observed a significant reduction in mean CMV with ULCD technique versus standard ACIS, respectively: angiogram 24.8 ± 15.8 mL (n = 194) vs 42.3 ± 25.1 mL (n = 200) (p < 0.0001); PCI 23.5 ± 19.7 mL (n = 52) vs 48.2 ± 30.8 mL (n = 16) (p < 0.0070); angiogram with ad hoc PCI 53.4 ± 32.1 mL (n = 23) vs 89.7 ± 35.6 mL (n = 16) (p < 0.0024); and overall angiogram and PCI 27.4 ± 20.5 mL (n = 204) vs 44.9 ± 28.0 mL (n = 181) (p < 0.0001). Conclusion Our study showed a highly significant reduction in CMV using ULCD technique compared to standard ACIS contrast delivery in coronary invasive procedures. Even in the standard ACIS arm, CMV was significantly lower than values reported in literature, possibly due to operators' bias toward contrast preservation.

The safety and effectiveness of 0.16 mg bevacizumab plus or minus additional laser photocoagulation in the treatment of retinopathy of prematurity

Purpose: Retinopathy of prematurity (ROP) is the leading cause of preventable blindness in premature infants. Antivascular endothelial growth factor (anti-VEGF) therapy has been used increasingly in treatment as a pharmacological alternative to laser therapy. In this study, we evaluate the results of low-dose anti-VEGF treatments. Methods: Design: Retrospective--observational study. Infants who had been evaluated for ROP disease between February 2016 and February 2017 were assessed. We retrospectively reviewed the ROP stages, treatment results, and complications. Laser photocoagulation (LPC) and intravitreal bevacizumab (0.16 mg IVB) were used for treatment and fundus fluorescein angiography (FFA) was also performed in some of the cases. Results: IVB was applied to 43 infants. A macular hole was seen in one infant's eye after IVB. LPC was applied to avascular areas in 21 infants. In three patients, persistence of the disease was observed after administration of a low dose of IVB. Additional LFK was performed in these patients. None of the infants who received LPC had any complications. Conclusion: IVB is increasingly becoming the first-line treatment for ROP. For severe ROP, 0.16 mg IVB is effective. Using LPC to treat avascular areas after 70 weeks' gestational age (GA) may decrease the risk of late recurrence and appears to be a safe treatment to use.

Laparoscopic transabdominal ultra-low anastomosis for rectal cancer: experience of 54 cases / 中国肿瘤临床

Objectives: To evaluate the safety and feasibility of ultra-low anastomosis for anal preservation in laparoscopic rectal can-cer surgery. Methods: The clinical data of 54 patients with low rectal cancer admitted to The Affiliated Hospital of Southwest Medical University from July 2014 to June 2017 were retrospectively analyzed. The short-term effect and complications were analyzed. Results:All patients underwent successful operations; conversion to laparotomy or death was not observed in any of the patients. The mean operative time was (165 ± 31) minutes, and the intraoperative bleeding volume was (12 ± 5) mL. There was no prophylactic ileostomy in all patients. Postoperative anastomotic bleeding and anastomotic leakage occurred in 2 and 3 cases, respectively; these complica-tions were managed with conservative treatment. Postoperative urination and sexual functions of the patients remained good, and most patients were satisfied with their anal function 1 year post-operation. No local recurrences or deaths were noted after follow-up for more than 2 years. However, liver metastases were detected in 3 patients 1 year post-surgery. Conclusions: Laparoscopic transab-dominal ultra-low anastomosis for rectal cancer has a good short-term effect; however, the long-term effect remains to be evaluated.

Selection of anal preservation surgery of low rectal cancer / 中国实用外科杂志

With the promotion of neoadjuvant therapy,the development of minimally invasive techniques and new surgical techniques,the anal preservation rate of low rectalcancer is increasing year by year. To improve postoperative quality of life is an important goal in the treatment of low rectal cancer. At present,the main important low anal preservation surgery is as follows: Intersphincteric resection(ISR),including complete ISR,subtotal ISR,partial ISR and modified partial ISR; Transanal local resection,including transanal endoscopic microsurgery(TEM) and transanal minimally invasive surgery(TAMIS); Anterior perineal planefor ultra-low anterior resection of the rectum(APPEAR),which is performed through a separate perineal incision,israrely used at present; Transanal total mesorectal excision(TaTME) proposed in recent years. Preliminary studies have proven safe and effective for low advanced rectal cancer.TaTME require a learning curve. It is now making expertcon sensus and operation specification,operation training and conducting multi-center prospective study. TaTME isexpected to become the important operation for low rectalcancer.

Clinical observation of laparoscopic abdominoperineal intersphincteric resection com-bined with ileostomy for treatment of ultra-low rectal cancer / 中国肿瘤临床

Objective: To observe and evaluate the clinical efficacy of laparoscopic abdominoperineal intersphincteric resection com-bined with ileostomy for the treatment of ultra-low rectal cancer. Methods: Clinicopathologic data of 74 patients undergoing laparo-scopic radical resection for ultra-low rectal cancer at Coloproctology Hospital of Chengdu from January 2015 to June 2017 were retro-spectively analyzed. In total, 43 patients underwent laparoscopic abdominoperineal intersphincteric resection combined with ileosto-my (ISR group), and 31 patients underwent laparoscopic low anterior resection combined with ileostomy (LAR group). The periopera-tive condition, radical resection of tumor, and postoperative anal function were compared between the two groups. Results: There were no significant differences in blood loss, postoperative hospital stay, and postoperative complications between the groups (all P>0.05). The mean operative time was (306.6 ± 25.1) minutes in the ISR group and (239.7 ± 26.4) minutes in the LAR group (P=0.010). There were no significant differences in pT and pN between the groups (all P values>0.05). The coincidence rate of T stage diagnosis was 93.0% in the ISR group and 93.5% in the LAR group. The positive rate of circumferential resection margin in the two groups was 0. The mean distance of the distal margin was (2.3±0.1) cm in the ISR group and (1.4±0.3) cm in the LAR group (P<0.001). All patients were followed up for 12-42 (mean 23.4) months. The local recurrence rate was 0 in the ISR group and 12.9% (4/31) in the LAR group (P=0.027); no distant metastasis was observed in any of the groups. There was no significant difference in the results of the anorectal manometry test between the groups (P>0.05). The proportion of patients with good continence of anal function after closure of ileos- tomy was 83.7% in the ISR group and 87.1% in the LAR group (P>0.05). Conclusions: Laparoscopic abdominoperineal intersphincteric resection combined with ileostomy is safe and feasible for the treatment of ultra-low rectal cancer, and it leads to satisfactory anal function and a short-term curative effect.

Feasibility of ultra low-dose coronary computed tomography angiography

There is an urgent need to develop new protocols to reduce radiation dose of coronary computed tomography angiography (CTA). The aim of this pilot study was to demonstrate the feasibility of an ultra-low dose CTA scanning.

Research progress of heparinase in the field of medicine / 生物工程学报

Heparinases can produce biologically active oligosaccharides by specifically cleaving the α-(1,4) glycosidic linkages of heparin and heparan sulphate. Heparinases are divided into heparinase and heparanase. Because heparinase is an effective biocatalyst, more and more researchers pay attention to the application of heparinase in medical field in the recent years. Combined with the related research work in our group, the application value of heparinase in the medical field was summarized, such as the determination of the structure of heparin, the preparation of low-molecular-weight heparin and ultra-low-molecular-weight heparin, tumor therapy and as a heparin antagonist. In addition, we summarized the definition, source of heparinase and its application in the medicine field. Heparinases have a great application prospect in the field of medicine.

Current state and progress of preserving anal function in treatment of low or ultral-low rectal cancer / 中国内镜杂志

As the development of society, people pay more attention to life quality. Nowadays, the therapeutic strategy to low or ultra-low rectal cancer has turned to anussaving as important as radical resection. Following the deep research in biology rule-rs of rectal cancer and a series of important theories, such as the 2 cm distal resection margin, total mesorectal excision technique, pelvic autonomic nerve preservation, variet-y of surgical methods can be chose in dealing with low or ultra-low rectal cancer a-nd achieving the goal of anus preservation. But, because of so many organs around the low or ultra-low rectal cancer and complicated anatomy, we should select patients strictly in order to avoid preserve one's anus blindly. if not, patients will face the condition of residual neoplasms or severe incontinence.

Effect of glass-infiltration treatments on the shear bond strength between zirconia and ultra low-fusing porcelain veneer / 대한치과보철학회지

PURPOSE: This study examined the effects of glass infiltration treatments on the shear bond strength (SBS) between zirconia core and ultra low-fusing porcelain veneer. MATERIALS AND METHODS: The zirconia specimens were classified into 4 groups (n = 12): Untreated zirconia (group Z), zirconia coated ZirLiner (group ZL), glass-infiltrated zirconia (group ZG), glass-infiltrated and sandblasted zirconia (group ZGS). A cylinder of ultra low-fusing veneer porcelain was build up on each disk (6 mm × 3 mm). SBS was measured using a universal testing machine. Scanning electron microscope and Energy Dispersive X-ray spectroscopy were used to evaluate the surface of zirconia and failure pattern after SBS. RESULTS: SBS value of group ZGS was significantly lower than that of other groups (P < .05). No significant differences were detected among group ZL, group Z and group ZG. CONCLUSION: Glass infiltration is not effective to the bond strength between zirconia and ultra low-fusing porcelain veneer. Sandblasting also dramatically decreased the bonding strength.

Evaluation of the dermatologic life quality among cleanroom workers in a secondary battery factory

BACKGROUND: Cleanroom air is extremely dry, as it is maintained within 1 % of relative humidity. Few studies have assessed the dermatologic life quality of workers in ultralow-humidity environments. Therefore, we aimed to evaluate the dermatologic life quality of cleanroom workers using the Skindex-29, compared to those of non-cleanroom workers. METHODS: Study participants were 501 cleanroom workers and 157 non-cleanroom workers from a secondary battery factory, who underwent an employee health examination at a single university hospital from September 2014 to September 2015. Results of the self-administered Skindex-29, and McMonnies questionnaire were analyzed. Other information and disease history were also collected during physician's medical examination. Descriptive and multivariate logistic regression analysis were performed. RESULTS: The Skindex-29 score was significantly higher in cleanroom workers than in non-cleanroom workers for all domains, Symptom (16.0 ± 15.9 vs. 6.3 ± 10.2, p < 0.001), Emotion (11.3 ± 17.4 vs. 2.5 ± 7.4, p < 0.001), Function (5.2 ± 11.1 vs. 1.6 ± 4.0, p < 0.001), and Overall (10.8 ± 13.4 vs. 3.5 ± 6.2, p < 0.001). The Skindex-29 score of cleanroom workers was similar to that of patients with skin diseases such as psoriasis, other dermatitis, corns, alopecia etc. Among the cleanroom workers, 37 workers had one or more skin diseases. Among the risk factors, ‘working at cleanroom’, ‘possessing skin disease’ and ‘McMonnies score’ had significant strong correlations with Skindex-29 score, meanwhile age, sex, smoking, drinking and exercise had weak correlations with it.‘Working at cleanroom’ and ‘possessing skin disease’ had highest odds ratios with overall 14.0 (C.I.: 5.9–33.1) and 13.4 (C.I.: 4.5–29.2), and the lowest odds ratios with function domain 3.5(C.I.: 1.7–7.1) and 4.5(C.I.: 2.1–9.5), respectively. The McMonnies score had the highest odds ratio with overall, 6.9(C.I.: 4.5–10.8) and lowest odd ratio with emotion domain 4.2 (C.I.: 2.7–6.4). CONCLUSIONS: Dermatologic life quality among cleanroom workers in the secondary battery factory is shown to be lower than that among non-cleanroom workers in this study. The study suggests that the Skindex-29 may provide helpful information on the dermatologic life quality of cleanroom workers. Therefore, regarding evaluation of dermatologic life quality using Skindex-29, preventive care is necessary for cleanroom workers in ultralow humidity environment.