Embedded Transdermal Alcohol Detection via a Finger Using SnO2 Gas Sensors

Enhance Ethanol Sensing Performance of Fe-Doped Tetragonal SnO2 Films on Glass Substrate with a Proposed Mathematical Model for Diffusion in Porous Media

This research enhances ethanol sensing with Fe-doped tetragonal SnO2 films on glass, improving gas sensor reliability and sensitivity. The primary objective was to improve the sensitivity and operational efficiency of SnO2 sensors through Fe doping. The SnO2 sensors were synthesized using a flexible and adaptable method that allows for precise doping control, with energy-dispersive X-ray spectroscopy (EDX) confirming homogeneous Fe distribution within the SnO2 matrix. A morphological analysis showed a surface structure ideal for gas sensing. The results demonstrated significant improvement in ethanol response (1 to 20 ppm) and lower temperatures compared to undoped SnO2 sensors. The Fe-doped sensors exhibited higher sensitivity, enabling the detection of low ethanol concentrations and showing rapid response and recovery times. These findings suggest that Fe doping enhances the interaction between ethanol molecules and the sensor surface, improving performance. A mathematical model based on diffusion in porous media was employed to further analyze and optimize sensor performance. The model considers the diffusion of ethanol molecules through the porous SnO2 matrix, considering factors such as surface morphology and doping concentration. Additionally, the choice of electrode material plays a crucial role in extending the sensor's lifespan, highlighting the importance of material selection in sensor design.

Ethanol endometrioma sclerotherapy: safety through 8 years of experience

STUDY QUESTION

What are the complications of transvaginal ethanol sclerotherapy for the treatment of endometriomas?

SUMMARY ANSWER

Sclerotherapy is a reliable, minimally invasive method applicable in outpatient procedures but with specific and potential life-threatening complications that need to be identified and prevented.

WHAT IS KNOWN ALREADY

There are currently few data on the use of transvaginal ethanol sclerotherapy, and we mainly note septic complications.

STUDY DESIGN, SIZE, DURATION

A retrospective observational cohort study was carried out. The study was conducted at an academic hospital and included 126 women aged 31.9 ± 5.5 years (mean ± SD), between November 2013 and June 2021. We analyzed a total of 157 ethanol sclerotherapy treatment (EST), treated by 131 EST procedures, in 126 women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study included women with an indication for transvaginal ethanol sclerotherapy. Indications were women with at least one endometrioma over 10 mm, isolated or associated with other endometriosis locations, requiring treatment for pain or infertility before assisted reproductive treatment. We followed a standardized transvaginal ethanol sclerotherapy procedure consisting of an ultrasound-guided transvaginal puncture of one or more endometriomas under general anesthesia. The cyst content was completely removed and flushed with saline solution. Ethanol (96%) was injected at 60% of the initial volume of the endometrioma, remained in the cyst for 10 min and was then completely removed. Ethanol loss was defined as a loss of 5 ml or more than 10% of the initial volume of the injected ethanol. Failure was defined by the contraindication of endometrioma puncture because of interposition of the digestive tract, ethanol loss in the previous endometrioma treated (in case of multiple ESTs), failure to aspirate the endometriotic fluid, contraindication to start ethanol injection owing to saline solution leakage, or contraindication to continue ethanol injection owing to suspicions of ethanol leakage at sonography. Intraoperative complications were defined by ethanol loss, positive blood alcohol level, and ethanol intoxication. Postoperative complications were defined by fever, biological inflammatory syndrome, and ovarian abscess. Complications were classified according to the Clavien and Dindo surgical classification, which is a system for classifying postoperative complications in five grades of increasing severity.

MAIN RESULTS AND THE ROLE OF CHANCE

We reported a total of 17/157 (10.8%) transvaginal ethanol sclerotherapy failures during 14/131 (10.7%) transvaginal ethanol sclerotherapy procedures in 13/126 (10.3%) women. In the same sets of data, complication was reported for 15/157 (9.5%) transvaginal ethanol sclerotherapy in 13/131 (9.9%) transvaginal ethanol sclerotherapy procedures in 13/126 (10.3%) women. Nine of 126 women (7.1%) had a grade I complication, one (0.8%) had a grade II complication (medical treatment for suspicion of pelvic infection), two (1.6%) had a grade III complication (ovarian abscess) and one (0.8%) had a grade IV complication (ethanol intoxication). We did not observe any grade V complications.

LIMITATIONS, REASONS FOR CAUTION

This was a retrospective study and pain assessment not considered. The benefit-risk balance of endometrioma transvaginal ethanol sclerotherapy was not evaluated.

WIDER IMPLICATIONS OF THE FINDINGS

Our study is the first to evaluate the complications of transvaginal ethanol sclerotherapy with such a large cohort of women in a standardized protocol. Transvaginal ethanol sclerotherapy seems to be an effective alternative to laparoscopic surgery in the management of endometriomas and limits the alteration of ovarian reserve. Transvaginal ethanol sclerotherapy is a reliable, minimally invasive method applicable on an outpatient basis. The majority of complications are Clavien-Dindo ≤IV, for which preventative measures, or at least early diagnosis and treatment, can be easily performed. The risk of ethanol intoxication is rare, but it is a life-threatening risk that must be avoided by appropriate implementation and promotion of the sclerotherapy procedures.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

Aix Marseille University's ethics committee registration number 2021-06-03-01.

An Effective Resistive-Type Alcohol Vapor Sensor Using One-Step Facile Nanoporous Anodic Alumina

With the increases in work environment regulations restricting alcohol to 1000 ppm, and in drink-driving laws, testing for alcohol with a simple method is a crucial issue. Conventional alcohol sensors based on sulfide, metal oxide, boron nitride or graphene oxide have a detection limit in the range of 50-1000 ppm but have disadvantages of complicated manufacture and longer processing times. A recent portable alcohol meter based on semiconductor material using conductivity or chemistry measurements still has the problem of a complex and lengthy manufacturing process. In this paper, a simple and effective resistive-type alcohol vapor sensor using one-step anodic aluminum oxide (AAO) is proposed. The nanoporous AAO was produced in one-step by anodizing low-purity AA1050 at room temperature of 25 °C, which overcame the traditional high-cost and lengthy process at low temperature of anodization and etching from high-purity aluminum. The highly specific surface area of AAO has benefits for good sensing performance, especially as a humidity or alcohol vapor sensor. With the resistance measurement method, alcohol vapor concentration of 0, 100, 300, 500, 700 and 1000 ppm correspond to mean resistances of 8524 Ω, 8672 Ω, 9121 Ω, 9568 Ω, 10,243 Ω, and 11,045 Ω, respectively, in a linear relationship. Compared with other materials for detecting alcohol vapor, the AAO resistive sensor has advantages of fast and simple manufacturing with good detection limits for practical applications. The resistive-type alcohol vapor-sensing mechanism is described with respect to the resistivity of the test substance and the pore morphology of AAO. In a human breath test, the AAO sensor can quickly distinguish whether the subject is drinking, with normal breath response of -30% to -40% and -20% to -30% response after drinking 50 mL of wine of 25% alcohol.