Disposable Tubes Research Articles

Design and Medical Effects of a Vaginal Cleaning Device Generating Plasma-Activated Water with Antimicrobial Activity on Bacterial Vaginosis

Bacterial vaginosis is a common female disease caused by a vaginal infection due to an overgrowth of bacteria that naturally live in the vaginal tract. Bacterial vaginosis has frequently been treated with the oral or vaginal administration of antibiotics and topical disinfectants. However, hygienic application of topical treatment deep in the vagina remains difficult. Herein, we introduce a novel vaginal cleaning device using plasma-activated water generated from supplied water. Remarkably, plasma source generation at atmospheric pressure is well known to eradicate bacterial infection through the generation of free radicals and/or chlorine chemicals with antimicrobial activity. The device was designed to alleviate a bacterial infection by spraying plasma-activated water generated from a cleaning solution container with plasma modules. The spray nozzle contains both a clean outlet and a suction outlet to spray and recover the plasma water, respectively, and is connected to a disposable silicone tube. The other nozzle, which has a laser light and air pump, can perform a second sterilization and dry the vagina after washing. Free chlorine chemicals with antibacterial activity were detected in the plasma-activated water by the device. Clinical application in patients with bacterial vaginosis confirmed the stability and effectiveness of our device. Therefore, these results show a novel clinical application of atmospheric pressure plasma to medical field as a plasma medicine.

Baleen-Mimicking Virtual Filters for Rapid Detection of Pathogenic Bacteria in Water Using Magnetic Nanoparticle Chains and a Halbach Ring.

We have developed a virtual filter that quickly and efficiently captures and detects pathogenic bacteria in large amounts of water. The virtual filter comprised magnetic nanoparticle chains (MNCs) obtained by cross-linking alginate-coated magnetic nanoparticles (MNPs). When the MNC solution in a disposable plastic tube was exposed to an external magnetic field, the MNCs were aligned along the magnetic field lines, forming a filter similar to a whale's baleen filtering system. A Halbach ring that increased the magnetic field inside the ring was used as the source of an external magnetic field. The Halbach ring produced a more uniform and denser alignment of MNCs than any other ring array. To demonstrate the performance of the virtual filter comprising MNCs, Escherichia coli (E. coli) O157-spiked water was injected into the virtual filter comprising polyethyleneimine-coated MNCs, and the concentration of E. coli O157 captured by electrostatic interaction was determined using qPCR analysis. The bacterial capture efficiency using MNCs was 90% at a flow rate of 5 mL/min, and the detection limit after 10 min of preconcentration of bacteria was 10 cfu/mL, which is 100 times lower than that obtained using qPCR alone.

Intercostal chest drain fixation strength: comparison of techniques and sutures

ObjectiveThe accidental removal of an intercostal chest drain (ICD) is common and may result in serious complications. A number of fixation techniques and suture material are in use, and the...

Two-side slug-flow microextraction coupled with ion mobility spectrometry for fast quantification of amphetamine and methamphetamine in human urine

In this study, first time a novel slug-flow microextraction (SFME) procedure named two-side SFME was developed and followed by ion mobility spectrometry equipped with corona discharge source (CD-IMS) for quantification of two abused drugs (amphetamine (AM) and methamphetamine (ME)) in urine samples. Regarding technique workflow, the organic extraction solvent (10 μL) was sandwiched between two portions of aqueous sample solution (the volume of each portion of sample solution was 5 μL) into a disposable glass capillary tube. The extraction of analytes was performed via the slug flows induced by the movements of the three liquids, which was conducted by tilting the glass capillary tube for several cycles. Finally, the extraction solvent was collected by a microsyringe and then injected (5 μL) into the CD-IMS. The effects of the effective parameters, including type of extraction solvent, number of tilting the glass capillary tube, and concentration of salt in sample solution were investigated. Under the optimized extraction condition (organic solvent: toluene; number of tilting the glass capillary tube: 10 times; concentration of salt: 5% (w/v)), the proposed two-side SFME/CD-IMS provided good linearity with coefficients of determination ≥0.993 over a concentration range of 25.0–2000.0 ng mL−1. Accordingly, acceptable limits of detection (S/N = 3) were 10.0 and 2.5 ng m‌‌L−1 for AM and ME, respectively. Furthermore, acceptable recoveries were ≥ 81.5, and ≥ 88.0% for AM and ME in a human urine sample, respectively, while repeatability and reproducibility ranged from 6.7 to 14.7% (n = 3).

Clinical application of self-made drainage tubes in different layers of soft tissue for negative-pressure wound therapy in 33 patients

From January 2014 to June 2018, 28 patients with different types of deep soft tissue injury or infection were admitted to the Affiliated Jiangyin Hospital of Medical College of Southeast University; 5 patients were admitted to the Zhengzhou First People's Hospital. There were 24 males and 9 females, aged 18-89 (40±20) years. Disposable suction tubes with holes cut on side walls were used as self-made drainage tubes. The authors placed the self-made drainage tubes on different deep soft tissue layers and wound surfaces after debridement. The effective drainage sections of the wound surface drainage tubes were wrapped with silver ion antimicrobial functional active dressings. Bio-permeable membrane was used to close the operative area. The drainage tubes in the deep layer of wound and wound surface were connected in parallel by a tee and connected to wall-hanging medical negative-pressure suction device to conduct negative-pressure wound treatment at -20.0 to -10.6 kPa. The deep drainage tubes were usually removed or changed 4 or 5 days after surgery.The drainage tubes in the wound surface were synchronously replaced when removing or replacing he drainage tubes in the deep layer of wound. On 4 to 15 days after surgery, the deep drainage tubes were removed. On 8 to 25 days after surgery, the wound surface drainage tubes were removed. Then the treatment was changed to a conventional dressing change until the wounds were completely healed or the wound bed was ready for skin grafts or tissue flaps. The indwelling time of deep drainage tubes in this group of patients was (6.2±2.8) days, and the indwelling time of wound surface drainage tubes was (12.0±3.0) days. The wound healing time was (22±5) days, the hospital stay time was (29±7) days, and wound bacteria were reduced from 6 species and 11 strains before treatment to 3 species and 4 strains after treatment. No adverse events such as wound bleeding, irritative pain, and chronic sinus occurred during treatment. Twenty-three patients were followed up for 13 to 28 months, no treatment-related complications were observed.

MORPHOLOGY OF EGGS CRASSICAUDA SP. FROM FECES OF PACIFIC BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS GILLII)

Initially, eggs Crassicauda sp. were found in the feces of the Pacific bottlenose dolphin (Tursiops truncatus gillii), which expands our knowledge of this nematode’s tropism, since crassicauda mainly inhabits the urogenital system or muscles. The material was volunteered from spontaneously infested 7-year-old female using a sterile disposable gastric tube Suyun (Unicorn Med) at Moskvarium. Feces were studied in the Center for Oceanography and Marine Biology laboratory (Moscow) by a direct smear method using Mikmed-5 light microscope (LOMO) and in the Laboratory for Study of Parasitic Diseases at the premises of the V.L. Yakimov Department of Parasitology of the St. Petersburg State Academy of Veterinary Medicine (St. Petersburg) using the crushed drop method and simple flotation method with Darling’s solution and further microscopy of temporary preparations in the Mikmed-6 light microscope (LOMO). Along with the morphometrically equal thickness of the multilayer egg membrane, the elongated part of the intact egg was optically inhomogeneous, which was even more noticeable in a damaged egg. Eggs with polar concavities of the inner layer and all of the layers of the membrane were found. The egg morphology indicates pliability of the polar structures of the membrane, which may be important when the larva emerges.

Protein precipitation coupled to paper spray with a tube for one-step analysis of blood.

Accurate measurement of trace compounds in blood samples is important in clinical diagnosis and life science. Ambient ionization mass spectrometry, however, suffers from the matrix effect when dealing with complex samples such as blood. Therefore, it is important to reduce the matrix effects in blood samples. A low-cost and disposable Teflon tube was used as a platform to precipitate the protein in blood. The analytes are extracted into organic solvent, and the precipitated protein can be adsorbed by the chromatography paper inserted. Therefore, the Teflon tube after precipitation can be directly subjected to paper spray ionization mass spectrometry, achieving one-step analysis of blood. High sensitivity and satisfactory stability were achieved for pharmaceuticals, acids, and endogenic metabolites in blood. The absolute signal intensities of characteristic product ions of the tested analytes were 8-20 times higher after protein precipitation than those obtained using paper spray. Detection limits and quantitative performance were evaluated for three drugs: carbamazepine, metformin, and tioconazole. In addition, the limits of detection and quantitation were improved 9-14- and 8-12-fold, respectively. Protein precipitation coupled to paper spray with a tube and then to mass spectrometry was successfully achieved and applied in the one-step analysis of trace compounds in blood samples. The experimental results showed that this method was sensitive, stable, convenient, and economic for the direct analysis of blood.

Application of Disposable Multifunctional Drainage Tube-Assisted Irrigation in Patients With Severe Multi-Space Infections in Oral and Maxillofacial Head and Neck Regions.

To compare the clinical efficacy of disposable multifunctional drainage tube (DMDT)-assisted irrigation with the traditional abscess incision rubber drainage technique in patients with severe multi-space infections in oral and maxillofacial head and neck regions. The data of 74 patients with severe multi-space infections in oral and maxillofacial head and neck regions, who were admitted to the Department of Oral and Maxillofacial Surgery, Central Hospital of Panzhihua City, Sichuan Province, China, between January 2015 and January 2019, were retrospectively studied. According to the treatment method, the patients were divided into 2 groups: the DMDT-assisted irrigation group and the abscess incision rubber drainage group. Cure rate, complications, length of hospitalization, days of antimicrobial use, cost of antimicrobial drugs, total hospitalization cost, number of dressing changes, and patient pain during dressing changes were compared between the 2 groups. Of the 74 patients, 38 were treated with the DMDT-assisted irrigation, and 36 with the traditional abscess incision rubber drainage. Compared with the traditional treatment group, the total hospitalization cost of the DMDT-assisted irrigation group is not much different (P = 0.72), but the patients in the DMDT-assisted irrigation group have higher cure rate, fewer complications, less antibiotics cost, shorter hospitalization length and fewer dressing changes than the control group (P < 0.05). The DMDT-assisted irrigation technique not only improves the cure rate, reduces complications, shortens hospitalization, reduces the use of antibiotics, and alleviates patient pain during dressing changes, but also improves clinical and therapeutic efficacy by reducing the number of dressing changes.

Determination of Moisture in Olive Oil: Rapid FT-NIR Spectroscopic Procedure Based on the Karl-Fischer Reference Method.

According to CODEX, moisture and volatile matter are olive oil quality parameters and the development of a rapid screening method for the determination of moisture is of interest. We recently demonstrated for the first time that the weak near-infrared (NIR) band near 5260 cm-1 is primarily attributed to a water O-H combination band. To determine the intensity of this band, we measured the peak-to-peak (p-p) height of its first derivative and generated exponential calibration curves for p-p height versus gravimetrically determined concentrations of spiked water in olive oils that had been purged of their initial moisture contents. To further optimize this univariate calibration method, calibration curves were generated in the present study based on plotting the moisture band first derivative p-p heights for neat olive oils (that were neither purged nor spiked) versus the moisture concentrations obtained by the Karl-Fischer (KF) primary reference method. To enhance the speed of FT-NIR data collection, measurements were carried in the transmission mode using disposable glass tubes. We also developed and compared a multivariate partial least squares approach to the univariate one. All the spectra were collected in two separate laboratories using two FT-NIR spectrometers of the same brand and model and no significant difference (p > 0.05) was found between the two laboratory determinations and the KF reference values at a 95% confidence interval. High accuracies were found with the two FT-NIR instruments used, as indicated by the low root mean squared error (RMSE, %) for predicted values obtained with the univariate procedure (RMSE = 0.008% and 0.010%) and the multivariate one, which yielded an even lower value (RMSE= 0.007% for both instruments). These results suggest that, once validated, the FT-NIR approach could potentially be a rapid substitute for the KF method.

Free hemoglobin reference intervals detected with hemoglobin-cyanide method on a biochemical automatic analyzer ILAB 300 PLUS

Objectives - to evaluate the reference intervals for free hemoglobin concentration with the help of hemoglobin-cyanide method and a biochemical automatic analyzer. Material and methods. The reference group consisted of 120 healthy men and 120 healthy women from the Astrakhan region aged from 20 to 60 years. The fulfilment of standard procedures during the pre-analytical prelaboratory, pre-analytical laboratory, analytical and post-analytical stages of the study ensured the quality control for free hemoglobin evaluation. Blood samples were taken with cubital vein puncture after applying a tourniquet (for not more than 1 minute), patient in lying position, using two-component blood sampling systems - disposable polypropylene tubes with a blood coagulation activator (Sarstedt, Germany). To obtain blood serum, blood tubes were centrifuged at 2500 rpm during 10 minutes. The free hemoglobin in blood serum was detected by the hemoglobin-cyanide method using a ILAB 300 PLUS biochemical automatic analyzer (Laboratory Instrumentation, USA). The data was processed using the software package Statistica 6.0 for Windows (StatSoft Inc, США). Results. We used the classical approach and followed the strict inclusion and exclusion criteria, recommended by CLSI C 28-A3 guidelines. Gender and age differences in the content of free hemoglobin in blood serum in men and women of the Astrakhan region were not found. The reference interval of free hemoglobin in men and women of the Astrakhan region was evaluated as 0.02-0.84 g/l.

New 'ZISIS' (Zigzag Incision-Suction-Irrigation System) Technique for Endoscopic-Assisted Forehead Tumour Excision.

Endoscopic-assisted excision of forehead tumours like osteomas and lipomas is well established, but the conventional techniques suffer from many limitations like inadequate access, fogging of the endoscope and unclear vision due to collection of blood and debris. Three simple modifications of the conventional endoscopic forehead techniquefor benign tumour excisionsare described by the acronym'ZISIS'. ZI Zigzag scalp incision increases the surface area of the opening permitting easy insertion of multiple instruments along with the endoscope.S Suction tubing made from a disposable suction catheter tube is taped along the endoscope sheath for continuous suctioning and good vision.IS Irrigation system of warm saline made with an infant feeding tube is also taped along the endoscope just opening in the front of the suction tube. A total of 12 consecutive patients underwent endoscopic excision of forehead benign tumours in 2years. This included 2 lipomas and 10 osteomas cases. All patients achievedexcellent hidden scars in the scalp. All patients rated their results as excellent with respect to the hidden scar and aesthetic result. No early or late complications were reported with follow-up ranging from 6months to 2years. A new simple modification called 'ZISIS' endoscopic forehead excision technique is described for benign forehead tumours excision making it easier, efficient and ergonomic. Evidence obtained from multiple time series with or without the intervention, such as case studies.

Application of self-made vacuum sealing drainage device in postoperative fixation and drainage of abdominal pedicled flaps in 8 patients with deep burns of upper limbs

From January 2013 to December 2017, 8 patients with deep burns of upper limbs were admitted to our hospital, including 6 males and 2 females, aged 23-48 years. The wound area of full-thickness burns to burns with tendon and bone injury was 4.5 cm×2.0 cm-20.0 cm×10.5 cm. After debridement, thin abdominal flaps with subdermal vascular network in the size of 5.0 cm×2.5 cm-22.0 cm×12.0 cm were applied to cover the wounds, and the donor sites were sutured directly by relaxation. The disposable suction tubes with holes cut on side walls were used as drainage tubes. The part of drainage tubes with holes were wrapped with nano-silver antimicrobial dressings and then placed at the lowest position of pedicle and donor site of abdominal flap and the space between the injured limb and the abdominal wall. The loose nano-silver antibacterial dressing was used to fill the webs of fingers and the gap between the injured limb and the abdominal wall. The transparent film dressing was used to close the surgical area and then connected with a low negative voltage electric suction device to continuously suck at a negative pressure of -15 to -10 kPa. The self-made vacuum sealing drainage device was replaced at intervals of 4 to 5 days until pedicle breakage was performed 2 to 3 weeks after operation. The pedicled abdominal flaps of 8 patients had no torsion or avulsion, no pedicle blood supply disorder, and no infection or skin erosion in the operation area, and all the flaps survived after pedicle breakage.

Time course detection of dihydrocodeine in body hair after a single dose

BackgroundWhen head hair is not suitable or not available, body hair, such as leg or beard hair might be the most suitable sample for drug hair analysis. Information about the time course of drugs in hair, from the different anatomical body sites, should still be well documented. AimThe aim of this study was to determine and compare (a) the detection window of dihydrocodeine in frequently shaved legs and beard, (b) in unshaved hair from head hair, chest hair, leg hair, and/or arm hair, and (c) the distribution concentrations over the scalp, after a single dihydrocodeine intake. MethodBefore a single intake of 12 mg dihydrocodeine by subject 1 (woman), both legs hair were shaved in the morning. The subject 2 (man) shaved his beard in the morning and 30 min later he had a dose of 10 mg of dihydrocodeine.The samples were washed with water and shampoo, dried and collected as follows: Subject 1: every 3-days shaved leg hair (n = 9) and 1-month-later head hair (n = 1). Subject 2: daily shaved beard hair (n = 15), 2 months later head hair (n = 145), and every 20 days unshaved arm, leg and chest hair (from different areas) (n = 4/area). The samples were analysed for dihydrocodeine using a validated liquid chromatography-tandem mass spectrometry method with a limit of quantification (LOQ) of 15.6 pg/mg for dihydrocodeine.About 20 mg of hair samples were weighted, washed with dichloromethane, centrifuged, dried, and pulverized in the same disposable tubes. Then the samples were incubated with methanol (under sonication at 45 °C) during 4 h. After centrifugation, the supernatant was evaporated and a cation exchange solid phase extraction followed by separation and quantification using ultra performance liquid chromatography-tandem mass spectrometry (ULC-MS/MS) was carried out. Chromatographic separation was achieved using a BEH phenyl column eluted with 0.1% formic acid: methanol (0.1% formic acid). The UPLC-MS/MS method was validated and used in routine for drug hair analysis for already several years. Results and discussionIn the present study leg hair was collected every 3 days, as an average of frequent shaved hair in western woman population. Shaved leg hair was very limited and only one hair sample was available per analysis. Beard was collected daily and in a higher amount. Dihydrocodeine was detected in leg hair from the first sample (3 days after the intake). Maximum concentration at 68 pg/mg for the single intake was obtained after 15 days (±2 days), decreasing later to the LOQ from the 21th day. Beard hair was positive from the first day sample, and the maximum concentration was observed at 66 pg/mg, 6 days after the intake, decreasing later to the LOQ from day 13. This may be explained by growth rate and the amount of growing hairs, in anagen phase. In other body hair samples, dihydrocodeine was negative or detected from 1 month after the intake. No significant differences in dihydrocodeine concentrations over the scalp in the different regions were observed (p > 0.05). ConclusionBody hair presents different time course window detection due to the different growth rates. Frequently shaved leg and beard hair may be suitable samples for recent single dihydrocodeine dose detection from the first days up to 2–3 weeks after the intake, respectively, when a LOQ of 15.6 pg/mg is applied.

Time course detection of dihydrocodeine in body hair after a single dose

When head hair is not suitable or not available, body hair, such as leg or beard hair might be the most suitable sample for drug hair analysis. Drugs may be detected in beard, from the first day up to more than one week. Specific information about the time course detection of drugs, after a single intake, in body hair has not been yet well documented for the different body hair samples. The aim of this study was to determine and compare the detection window of dihydrocodeine in frequently shaved legs and beard after a single intake. Unshaved hair from head hair, chest hair, leg hair, and/or arm hair were also analysed. Before a single intake of 12 mg dihydrocodeine by test subject 1 (female), the leg hair was shaved in the morning. The second test subject 2 (male) shaved his beard in the morning and 30 min later he had a dose of 10 mg of dihydrocodeine. The samples were washed with water and shampoo, dried and collected as follows: subject 1: every 3-days shaved leg hair ( n = 10) and 1-month-later head hair ( n = 1). Subject 2: daily shaved beard hair ( n = 15), 2 months later head hair ( n = 50, different regions), and every 20 days unshaved arm, leg and chest hair (from different regions) ( n = 4/area). The samples were analysed for dihydrocodeine using a validated liquid chromatography tandem mass spectrometry method with a limit of quantification (LOQ) of 16 pg/mg for dihydrocodeine. About 20 mg of hair samples were weighted, washed with dichloromethane, centrifuged, dried, and pulverized in the same disposable tubes. Then the samples were incubated with methanol (under sonication at 45 °C) during 4 h. After centrifugation, the supernatant was evaporated and a cation exchange solid phase extraction followed by separation and quantification using ultra performance liquid chromatography tandem mass spectrometry (UHLC-MS/MS) was carried out. Chromatographic separation was achieved using a BEH phenyl column eluted with 0.1% formic acid: methanol (0.1% formic acid). The UPLC-MS/MS method was validated and used in routine for drug hair analysis for already several years [1] . In the present study leg hair was collected every 3 days, as an average of frequent shaved hair in western woman population. Leg hair was very limited and only one hair sample from both woman legs was available per analysis. Beard was collected daily and in a higher amount. Dihydrocodeine was detected in leg hair from the first sample (3 days after the intake). Maximum concentration at 68 pg/mg for the single intake was obtained after 15 days (± 2 days), decreasing later to the LOQ from the 21st day. Beard hair was already positive from the first day sample, and the maximum concentration was observed at 66 pg/mg, 6 days after the intake, decreasing later to the LOQ from day 10. This may be explained by the ‘Richards–Meharg body and head hair growth table, where it indicates that legs have only 20% of growing hairs in anagen phase, while beard goes from 50 to 70%. In other body hair samples, dihydrocodeine was negative or detected from 1 month after the intake. Body hair presents different time course window detection due to the different growth rates. Frequently shaved leg and beard hair may be suitable samples for recent single dihydrocodeine dose detection from the first days up to 21 or 13 days after the intake, respectively, when an LOQ of 16 pg/mg is applied.

3D-printed Point-of-Care Platform for Genetic Testing of Infectious Diseases Directly in Human Samples Using Acoustic Sensors and a Smartphone.

The objective of this work is to develop a methodology and associated platform for nucleic acid detection at the point-of-care (POC) that is sensitive, user-friendly, affordable, rapid, and robust. The heart of this system is an acoustic wave sensor, based on a Surface Acoustic Wave (SAW) or Quartz Crystal Microbalance (QCM) device, which is employed for the label-free detection of isothermally amplified target DNA. Nucleic acids amplification and detection is demonstrated inside three crude human samples, i.e., whole blood, saliva, and nasal swab, spiked in with 10-100 Salmonella cells. To qualify for POC applications, a portable platform was developed based on 3D printing, integrating inside a single box: (i) simple fluidics based on plastic tubing and a mini peristaltic pump, (ii) a heating plate combined with disposable reaction tubes for isothermal amplification; (iii) a mini antenna analyzer operated through a tablet; and (iv) an acoustic wave device housing unit. The simplicity of the method combined with smartphone operation and detection, rapid sample-to-answer analysis time (30 min), and high performance (detection limit 4 × 103 CFU/ml) in three of the most important human samples in diagnostics suggest that the methodology could become a tool of choice for nucleic acid detection at the POC. In addition, the low cost of the platform and assay holds promise for its adoption in resource limited areas. The acoustic detection method is shown to give similar results with a standard colorimetric assay carried out in saliva and nasal swab but can also be used to detect nucleic acids inside whole blood, where a colorimetric assay failed to perform.

Influence of bleaching and thermal straightening on endogenous GHB concentrations in hair: An in vitro experiment

Since gamma-hydroxybutyric acid (GHB) is present in hair of the general population under physiological concentrations, special attention has to be given to the hair analysis of GHB and its interpretation. Normal levels of endogenous GHB can vary in each individual. As a result, strands of hair from a subject have to be cut in small segments (0.3–0.5 cm long) with analysis of each segment. As such, each subject can be used as its own control with a continuous endogenous signal. If one segment has a GHB concentration 10 times higher than the others, this suggests possible administration of exogenous GHB according to the UNODC guideline for Drug Facilitated Assault Cases. AimAs cosmetic treatments were found to decrease drug concentrations in hair, the aim of the study was to develop an UPLC®–MS/MS method for the analysis of GHB in hair. An in vitro study was then carried out in order to evaluate the impact of a hair straightener or a bleaching treatment on endogenous GHB concentrations. MethodHair samples (10 mg) were washed with dichloromethane and water. After drying overnight in an oven at 35 °C the samples were pulverized in disposable plastic tubes. Methanol/acetonitrile/ammonium formate buffer 1 mM (25:25:50, v/v/v) was used to extract the drug from the hair matrix in a water bath for 1.5 h at 37 °C. Thereafter, the samples were filtered and evaporated to dryness. The dried extracts were then reconstituted in mobile phase and injected in a UPLC®–MS/MS (Waters, Winslow, UK) with a BEH C18 column. ResultsThe method was validated using untreated hair samples from three healthy volunteers. The calibration curve ranged from 0.06 to 25 ng/mg and the repeatability and intra-batch precision was lower than 20% evaluated in 8 different batches. Processed samples were stable for 3 days in the auto-sampler. To demonstrate the method applicability, 54 hair samples from healthy volunteers were analysed for endogenous GHB resulting in a concentration range from 0.2 to 6 ng/mg.Three different hair treatments experiments were carried out, in which a hair straightener and/or a bleaching treatment were applied. These experiments demonstrated that hair treatments decreased up to 80% of the GHB endogenous concentrations. ConclusionThis in vitro study showed that hair bleaching or a heat source treatment influences GHB concentrations in hair. For a correct interpretation of GHB results in hair, cosmetic treatments should be considered, certainly in cases where only a part of the hair is treated.

Nosocomial transmission of hepatitis C virus in a liver transplant center in Hong Kong: implication of reusable blood collection tube holder as the vehicle for transmission.

A liver transplant recipient developed hospital-acquired symptomatic hepatitis C virus (HCV) genotype 6a infection 14 months post transplant. Standard outbreak investigation. Patient chart review, interviews of patients and staff, observational study of patient care practices, environmental surveillance, blood collection simulation experiments, and phylogenetic study of HCV strains using partial envelope gene sequences (E1-E2) of HCV genotype 6a strains from the suspected source patient, the environment, and the index patient were performed. Investigations and data review revealed no further cases of HCV genotype 6a infection in the transplant unit. However, a suspected source with a high HCV load was identified. HCV genotype 6a was found in a contaminated reusable blood-collection tube holder with barely visible blood and was identified as the only shared item posing risk of transmission to the index case patient. Also, 14 episodes of sequential blood collection from the source patient and the index case patient were noted on the computerized time log of the laboratory barcoding system during their 13 days of cohospitalization in the liver transplant ward. Disinfection of the tube holders was not performed after use between patients. Blood collection simulation experiments showed that HCV and technetium isotope contaminating the tip of the sleeve capping the sleeved-needle can reflux back from the vacuum-specimen tube side to the patient side. A reusable blood-collection tube holder without disinfection between patients can cause a nosocomial HCV infection. Single-use disposable tube holders should be used according to the recommendations by Occupational Safety and Health Administration and World Health Organization.

A Simple and Low-cost Drilling Simulator for Training Plunging Distance Among Orthopedic Surgery Residents

Drilling through bone is a complex action that requires precise motor skills of an orthopedic surgeon. In order to minimize plunging and soft tissue damage, the surgeon must halt drill progression precisely following penetration of the far cortex. The purpose of this study was to create a low-cost and easy-to-use drilling simulator to train orthopedic residents in reducing the drill plunging depth. This prospective observational study was performed in the division of orthopedic surgery of a single tertiary medical center. The participants included 13 residents and 7 orthopedic specialists. The simulator consisted of a synthetic femur bone model and ordinary modeling clay, and the training unit consisted of a disposable plastic tube (∼US$14), clamps (∼US$58), and a power drill + drill bit (standard hospital equipment). Plunging depths were measured by the simulator and compared between orthopedic specialists, the 6 "senior residents" (3+ years) and the 7 "junior residents" during a training session. Measurements were taken again 2 weeks following the training session. Initially, the plunging depths of the junior residents were significantly greater compared to those of the orthopedic specialists (7.00 mm vs. 5.28 mm, respectively, p < 0.038). There was no similarly significant difference between the senior residents and the orthopedic experts ([6.33 mm vs. 5.28 mm, respectively; p = 0.18). The senior residents achieved plunging depths of 5.17 mm at the end of the training session and 4.7 mm 2 weeks later compared to 7.14 mm at the end of the training session and 6 mm 2 weeks later for the junior residents. This study demonstrated the capability of a low-cost drilling simulator as a training model for reducing the plunging depth during the drilling of bone and soft tissue among junior and senior residents.

Initial development of Physalis seedlings in substrates and containers

The objective of this study was to evaluate the growth of Physalis peruviana and Physalis pubescens in containers and substrates, as well as the growth of transplanted P. pubescens seedlings into different containers and substrates. It was used for transplanting experiment (E1) plastic bags, disposable plastic glasses and plastic tubes containing four substrates: oxisol; commercial substrate; commercial substrate + fine washed sand; and commercial substrate + oxisol + fine washed sand. For the experiment of containers x substrates (E2) it was used polystyrene and polypropylene trays, both with 200 cells containing two substrates: vermiculite + commercial substrate and vermiculite + oxisol. For the experiment of containers x substrates (E3), it was used polystyrene trays with 128 and 200 cells and plastic tubes containing four substrates: commercial substrate, oxisol, fine washed sand, oxisol + fine washed sand and oxisol + fine washed sand + commercial substrate. The experimental design used in E1, E2 and E3 was randomized blocks in factorial 3x4, 2x2, and 3x5, respectively, containing 4 replicates and 10 plants per plot. The use of commercial substrate Húmus Fértil® for P. pubescens seedlings transplanted from seedbed to containers such as plastic glasses or plastic bags provides better seedling growth. For Physalis peruviana, better results are verified in the use of polypropylene tubes containing washed fine sand + commercial substrate Húmus Fértil® + oxisol or washed fine sand + oxisol. Better results for formation of P. pubescens seedlings were verified by using expanded polystyrene trays containing oxisol + vermiculite mixture.

Online Monitoring of Bacterial Growth with an Electrical Sensor.

Herein, we developed an automatic electrical bacterial growth sensor (EBGS) based on a multichannel capacitively coupled contactless conductivity detector (C4D). With the use of the EBGS, up to eight culture samples of E. coli in disposable tubes were online monitored simultaneously in a noninvasive manner. Growth curves with high resolution (on the order of a time scale of seconds) were generated by plotting normalized apparent conductivity value against incubation time. The characteristic data of E. coli growth (e.g., growth rate) obtained here were more accurate than those obtained with optical density and contact conductivity methods. And the correlation coefficient of the regression line ( r) for quantitative determination of viable bacteria was 0.9977. Moreover, it also could be used for other tasks, such as the investigation of toxic/stress effects from chemicals and antimicrobial susceptibility testing. All of these performances required neither auxiliary devices nor additional chemicals and biomaterials. Taken together, this strategy has the advantages of simplicity, accuracy, reproducibility, affordability, versatility, and miniaturization, liberating the users greatly from financial and labor costs.