Syringe Needle Research Articles

Monodisperse CaCO3-loaded gelatin microspheres for reversing lactic acid-induced chemotherapy resistance during TACE treatment

Transarterial chemoembolization (TACE) is an important approach for the treatment of unresectable hepatocellular carcinoma (HCC). However, the lactic acid-induced acidic tumor microenvironment (TME) may reduce the therapeutic outcome of TACE. Herein, monodispersed gelatin microspheres loaded with calcium carbonate nanoparticles (CaNPs@Gel-MS) as novel embolic agents were prepared by a simplified microfluidic device. It was found that the particle size and homogeneity of as-prepared CaNPs@Gel-MS were strongly dependent on the flow rates of continuous and dispersed phases, and the inner diameter of syringe needle. The introduction of CaNPs provided the gelatin microspheres with an enhanced ability to encapsulate the chemotherapeutic drug of DOX, as well as a pH-responsive sustained drug release behavior. In vitro results revealed that CaNPs@Gel-MS could largely increase the cellular uptake and chemotoxicity of DOX by neutralizing the lactic acid in the culture medium. In addition, CaNPs@Gel-MS exhibited an excellent and persistent embolic efficiency in a rabbit renal model. Finally, we found that TACE treatment with DOX-loaded CaNPs@Gel-MS (DOX/CaNPs@Gel-MS) had a much stronger ability to inhibit tumor growth than the DOX-loaded gelatin microspheres without CaNPs (DOX@Gel-MS). Overall, CaNPs@Gel-MS could be a promising embolic microsphere that can significantly improve anti-HCC ability by reversing lactic acid-induced chemotherapy resistance during TACE treatment.

Overview of Recent Development of Needle-Trap Devices for Analysis of Volatile Compounds

Needle-trap devices (NTDs) are another sorbent-based tool in the haystack of methods used in analytical extractions. Syringe needles, similar to those used for gas chromatography (GC) injection, can be partially filled with suitable sorbents and are used for extracting and collecting volatile organics, followed by injection into a GC instrument via thermal desorption. Although NTDs share many similarities and advantages of solid-phase microextraction (SPME), the larger sorbent bed provides robustness and offers potentially exhaustive extractions. This month, we take a look at the principles and applications of NTDs, and recent developments in their use.

Effect of various volume syringes on solution delivery time using conventional irrigation technique in 0.04 tapered preparations of single straight root canals

Introduction: The important aspect of endodontic treatment is root canal irrigation. Although agitation systems proved to have enhanced irrigant wall interactions, syringe needle-based delivery systems still play a significant role during the preparatory phases of root canal treatment. The current study aimed to evaluate the time taken for the irrigant delivery during conventional syringe irrigation using different volume syringes in different root canal preparations. Materials and Methods: Two hundred extracted single-rooted premolars with approximately round canals were randomly instrumented to preferred apical preparation sizes using 0.4 tapered Hyflex-CM rotary Ni-Ti instruments and randomly divided as follows: Group I, instrumentation to size 40, 0.04 taper (n = 50); Group II, instrumentation to size 30, 0.04 taper (n = 50); Group III, instrumentation to size 25, 0.04 taper (n = 50); and Group IV, instrumentation to size 20, 0.04 taper (n = 50). Fifty operators were chosen for the experimentation. They were asked to irrigate the prepared specimens using different volume syringes. The entire irrigant delivery time was recorded by a head nurse using a stopwatch, and the values were calibrated and statistically analyzed. Results: Group I recorded significantly lesser time for irrigant delivery during manual syringe needle irrigation (P = 0.005) compared to other groups. Conclusion: Irrigation delivery time was less in 40/0.04 taper preparations, using 1 ml volume syringes.

Mammalian cell encapsulation in monodisperse chitosan beads using microchannel emulsification

Microchannel emulsification can produce droplets of uniform size at high throughput for wide-ranging applications in the food and drug industry. Mammalian cell encapsulation using emulsion-based systems is of significant interest for immobilized culture or transplantation applications. Microchannel emulsification has recently been applied to mammalian cell encapsulation using alginate. Here, we extend this approach to thermoresponsive hydrogels using chitosan as a model. The performance of the microchannel emulsification process was compared to a previously established stirred emulsification method for mesenchymal stromal cell encapsulation. Chitosan microbeads with controlled sizes ranging from 600 µm to 1500 µm in diameter at a coefficient of variation less than 10 % were obtained after adapting the microchannel system design, channel geometries and operating parameters that affect the capillary number. In a single pass through a 21 G syringe needle, the fraction of ruptured beads was significantly reduced for monodisperse microchannel-generated vs polydisperse stirred emulsion-generated beads of matching De Brouckere mean diameter. The viability of the immobilized cells immediately after the process was 95 % ± 2 % and no significant difference in cell survival and growth factor secretion was observed between microchannel and stirred emulsion-generated beads over 3 days of culture. Microchannel emulsification is a promising and scalable approach to microencapsulate mammalian cells in hydrogels that undergo temperature-dependent gelation.

Self-Forming Norbornene-Tetrazine Hydrogels with Independently Tunable Properties.

Although photopolymerization reactions are commonly used to form hydrogels, these strategies rely on light and may not be suitable for delivering therapeutics in a minimally invasive manner. Here, hyaluronic acid (HA) macromers are modified with norbornene (Nor) or tetrazine (Tet) and upon mixing click into covalently crosslinked Nor-Tet hydrogels via a Diels-Alder reaction. By incorporating a high degree of Nor and Tet substitution, Nor-Tet hydrogels with a broad range in elastic moduli (5 to 30kPa) and fast gelation times (1 to 5 min) are achieved. By pre-coupling methacrylated HANor macromers with thiolated peptides via a Michael addition reaction, Nor-Tet hydrogels are peptide-functionalized without affecting their physical properties. Mesenchymal stem cells (MSCs) on RGD-functionalized Nor-Tet hydrogels adhere and exhibit stiffness-dependent differences in matrix mechanosensing. Fluid properties of Nor-Tet hydrogel solutions allow for injections through narrow syringe needles and can locally deliver viable cells and peptides. Substituting HA with enzymatically degradable gelatin also results in cell-responsive Nor-Tet hydrogels, and MSCs encapsulated in Nor-Tet hydrogels preferentially differentiate into adipocytes or osteoblasts, based on 3D cellular spreading regulated by stable (HA) and degradable (gelatin) macromers.

PH-Responsive, Thermo-Resistant Poly(Acrylic Acid)-g-Poly(boc-L-Lysine) Hydrogel with Shear-Induced Injectability.

In this study we report the rheological behavior of aqueous solutions of an amphiphilic graft copolymer constituting a polyacrylic acid (PAA) grafted by poly(boc-L-lysine), P(b-LL). Due to the highly hydrophobic nature of the grafted chains, the copolymer self-assembles spontaneously in aqueous media forming three-dimensional (3D) finite size networks (microgels). The rheological analysis demonstrated that the copolymer behaves as a strong elastic hydrogel, showing characteristics of a "frozen" network. Moreover, it is noteworthy that the formulation shows the above-described characteristics in very small concentrations (0.25-1.20 wt%) compared to other naturally cross-linked hydrogels that have been studied so far. Concentration significantly affects the rheological properties of the hydrogel, showing considerable increase in elastic modulus, following the scaling law G'~C1.93. At the same time, the hydrogels can be described as intelligent stimuli-responsive systems, showing pH and shear responsiveness as well as stability with temperature changes. Thanks to the pH dependance of the degree of ionization of the weak polyelectrolyte PAA backbone, stiffness and swelling of the hydrogels can be tuned effectively by adjusting the pH conditions. Simulating conditions such as those of injection through a 28-gauge syringe needle, the gel demonstrates excellent response to shear, due to its remarkable shear thinning behavior. The combination of pH-sensitivity and shear responsiveness leads to excellent injectability and self-healing properties, given that it flows easily upon applying a low stress and recovers instantly in the site of injection. Therefore, the physically cross-linked PAA-g-P(b-LL) hydrogel exhibits remarkable features, namely biocompatibility, biodegradability of cross-links, pH responsiveness, shear-induced injectability and instantaneous self-healing, making it a potential candidate for various biomedical applications.

Evaluating occupational exposures of dental nurses: A retrospective study.

The objective of this study was to investigate occupational blood-borne pathogen exposure among dental nurses and their attitudes toward infected patients, as well as the effectiveness of the training course, to provide a scientific basis for improving the quality of safety management in the dental hospital. The study was conducted using questionnaires administered from November 2019 to December 2019 in three hospitals in Sichuan Province, China. Frequencies for answers were calculated and presented as percentages. In total, 257 valid questionnaires were returned. Most (61.9%) nurses stated that they were involved in occupational exposure. Among them, 154 had experienced sharp injuries, and the syringe needle was the most common instrument for injuries (45.8%). Twenty-two individuals had mucosal exposure, and the proportion of eye exposure was the highest (90.9%). Only associations between training and mucosal membrane exposure were found; however, the relevance was weak (r = 0.141). Of the participants, 86.4% felt morally responsible for taking care of patients with infectious diseases, and most (92.6%) said they would continue with this career. Occupational exposure, particularly to sharp injuries, was common in medical care among dental nurses; however, vocational training had little effect on their incidence. As dental nurses still have positive attitudes toward patients with infectious diseases, more effective training should be conducted.

Prevalence of needlestick injuries and factors associated with their occurrence among health care workers at a private hospital in northern Namibia

BackgroundAlthough needle stick injuries (NSIs) are a very common preventable occupational hazard among healthcare workers (HCWs), their prevalence remains high. The study aimed to assess the prevalence of NSIs, and factors associated with NSIs among HCWs at a private hospital in northern Namibia. The HCWs included enrolled nurses, registered nurses, and doctors. MethodsAn analytic cross-sectional study design was used for the study. 400 respondents were selected using a proportional stratified random sampling method. A self-administered questionnaire designed for the study was used for data collection. Statistical analysis employed Chi-square tests and logistic regression. ResultsThe 12 months prevalence rate of NSIs among HCWs was 37.5%, 95% CI (32.8% – 42.2%), while the career prevalence was 55.3%, 95% CI (50.4% – 60.2%). Most NSIs (30.3%) occurred in theatre, 40.3% were caused by syringe needles, 70.5% occurred on fingers, and 74.7% were of a prick nature. Chi-square tests showed an association between profession and NSIs and between work experience and NSIs (p<0.01). Nurses were more likely to experience NSIs in the past 12 months compared to doctors, AOR = 4.31, 95% CI (1.50 – 12.38). Respondents with 2-5 years of work experience were less likely to experience NSIs in the past 12 months compared to those with less than two years of work experience, AOR = 0.36, 95% CI (0.21 – 0.62). ConclusionThe findings of the study accentuate the need for hospital authorities to strengthen employees’ training on handling sharp instruments and support the use of instruments with safety features.

Evaluation of a septumless mini-cartridge for automated solid-phase extraction cleanup in gas chromatographic analysis of >250 pesticides and environmental contaminants in fatty and nonfatty foods

The QuEChERSER mega-method has recently been introduced to quantify and identify a wide range of chemical residues (pesticides, veterinary drugs, environmental contaminants, among others) in nearly all types of foods. The approach calls for taking a small amount of the initial extract to cover analytes amenable to liquid chromatography, and the remainder is salted out for analysis by gas chromatography (GC), both with mass spectrometry (MS) based detection. In the case of GC-MS(/MS), the extract undergoes automated robotic mini-cartridge solid-phase extraction (SPE) cleanup in a technique known as µSPE or instrument-top sample preparation (ITSP). In 2022, a septumless mini-cartridge for µSPE was introduced to improve upon the ITSP design. The new design houses a bed of 20 mg anhydrous MgSO4, 12 mg each of C18 and primary secondary amine sorbents, and 1 mg of graphitized carbon black, the latter substituting for CarbonX used in the ITSP product. The septumless µSPE mini-cartridge employs a different gripping mechanism with the syringe needle that allows leak-free operation at higher flow rates (e.g. 10 µL/s), whereas the ITSP design is limited to 2 µL/s. Based on cleanup and analyte elution profiles, the extract load volume and flow rate was increased in µSPE for QuEChERSER from 300 µL at 2 µL/s to 500 µL at 5 µL/s, which improved accuracy of results, sped the cleanup step, and obviated the need for micro-vial inserts in the receiving vials. The new design also reduced both the amount and consistency of dead (void) volumes in the mini-cartridges from 83 ± 14 µL to 52 ± 7 µL for 200-600 µL load volumes. Normalization of peak areas to internal standards led to recoveries between 80 and 120% with typical RSDs <5% in low-pressure GC-MS/MS of 227-242 out of 252 pesticides, polychlorinated biphenyls, polybrominated diphenyl ethers, and polycyclic aromatic hydrocarbons in hemp powder, spinach, whole milk, egg, avocado, and lamb meat.

Prevalence of Sharp Injuries and Associated Factors among Healthcare Workers in North Gondar (Debark), West Gondar (Metema), and South Gondar (Addis Zemen) Primary Hospitals, Northwest Ethiopia

Objectives: Occupation-related sharp injuries are a global problem; the death toll is around 2 million and is rising in low-income nations like Ethiopia. No information has been reported on sharp injuries in North and South Gondar primary hospitals and present study aims to determine the prevalence of sharp injuries among healthcare workers. Methods: A institutional crosssectional study conducted and 351 were randomly chosen. A self-administered questionnaire was used to collect data and analyzed with SPSS ver23. Bivariate analysis and Multiple logistic regression were used to understand confounding factors. Findings: The prevalence of sharp injuries among Healthcare workers (HCWs) lifetime and preceding 12 months were 131 (37.3%) and 86 (24.5%), respectively, of which 76 (58%) and 47 (54.65%) were reported by females. The chance of recurrent incidence of sharp injuries was more in operation theatre (37.5%). The primary source of injury was syringe needles 52 (42.5%). HCWs >10 years of work experience are more likely to experience sharp injuries compared to those less experience (<5 years) [AOR: 0.40, 95% CI: (0.21, 0.79)]. Never had any training on sharp injuries were more likely to report a sharp injury compared to those reported training [AOR: 0.55, 95% CI: (0.3, 1.024)]. Worked more than 48 hours/week reported more likely sustained sharp injuries [AOR: 0.95, 95% CI: (0.93, 0.98)]. HCWs dissatisfied with their work environment reported sharp injuries more than satisfied ones [AOR = 0.34, 95% CI: (0.2, 0.6)]. Similarly, having low [AOR: 0.26, 95% CI: (0.13, 0.56)] and moderate risk perception [AOR: 0.36, 95% CI: (0.19, 0.67)] significantly raised the odds of sharp injuries occurrence compared to a high-risk perception for sharp injuries. Novelty/conclusion: Present study showcases the moderate risk perception, work hours more than 48 h/week were the key factors identified, along with job dissatisfaction, lack of training and avoiding recapping may reduce the injury burden. Keywords: Amhara; Ethiopia; Hospital; Nurse; Occupational injury 1

Backflow modeling in nanofluid infusion and analysis of its effects on heat induced damage during magnetic hyperthermia

• Simulate the backflow behavior for nanofluid infusion inside bio-tissue under a geometric nonlinear model. • Investigate the bio-tissue deformation and its effect on the change of material property during nanofluid infusion. • Investigate the interstitial pressure and the local stress distribution inside bio-tissue due to the nanofluid infusion. • Effect of backflow on treatment temperature distribution and heat induced damage for malignant tissue. Although targeted magnetic hyperthermia has been proven to be an effective tumor ablation technique, its use in clinical applications is still scarce particularly due to the difficulty in imposing a desired nanofluid distribution in the therapeutic area. In addition to the inherent difficulty of imposing a distribution with few injection shots, during the nanofluid infusion, the tissue deformation can cause the nanofluid deviation from the targeted injection area and the backflow along the needle can deliver the injected nanofluid to the outer surface of the tissue. Both phenomena can result in an irregular distribution for nanofluid inside bio-tissue. This study develops a poroelastic model considering geometrically nonlinear behavior in order to evaluate the effect of syringe needle size and infusion rate on the backflow. A 26 gauge needle for syringe is used as a typical example to further investigate the nanofluid transport and the change of solid matrix material properties under different infusion rates after comparing the infusion results for several sizes of needle. Finally, the resulting nanofluid concentration distribution obtained with the proposed model is used to simulate the temperature distribution and the cancerous cell damage. The results demonstrate that the infusion pressure and its resulting tissue deformation are the fundamental reasons for obtaining an irregular solution distribution. Tissue deformation induces the increase of porosity and permeability for biomaterials around the tip, and enhances the fluidity of nanofluids inside the tissue. The results also indicate that the increase in backflow length can improve the uniformity of the nanofluid distribution after diffusion and, consequently, the treatment effect. However, it also increases the risk of MNP leakage from the targeted area to the tumor surface, so it is important to keep the backflow rate limited during the injection process.

Optimizing Fabrication of Electrospinning Nanofiber Membranes for Water Filtration using Response Surface Methodology

Nanofiber Polyethersulfone (PES) membrane fabrication using the electrospinning method incorporating dry/wet phase inversion was investigated. The electrospinning process is a straightforward and versatile method to produce one-dimensional nanostructures, especially nanofibers. The electrospun’s outcome can be affected by the various process parameters and solution parameters, making it an interesting study subject and an opportunity for customized nanofiber membrane. In this work, the analysis includes dope formulation and electrospinning parameter influence to membrane morphology dimensional structure based on Scanning Electron Microscopy (SEM) and filtration capability. Fibrous membranes were electrospun at 1 to 3 ml/h feeding rate and at 12 to 25kV voltage rate in a fixed 10 to 12 cm distance between the filter membrane and the syringe needle tip. The PES dope solution with N-methyl-2-pyrrolidone (NMP) as solvent electrospun onto a wet filter base membrane (5A 90 mm Advantec Filter Paper) to refine the fabricated fibrous membrane and to induce the dry-wet phase inversion process. The results indicate that the PES fiber dimension reduced at a lower feeding rate and higher voltage rate. In terms of liquid separation performance, experimental results showed that pure water permeation flux was reduced with the increased flow spinning rate of 1 to 3ml/hr but triple times higher than the increased concentration PES formulation, even at higher voltage spinning. The electrospun performance of polyethersulfone was also explained using Response Surface Methodology (RSM). It focused on the polymer content, tip-to-collector distance, and flow rate parameters toward fiber diameter and contact angle. Among these factors, the effect of PES content (f-value = 65.87) was the most significant, followed by tip-to-collector distance (f-value = 11.26) and flow rate (f-value = 2.59).

Bibliometric analysis on key elements of clinical application of acupoint catgut embedding therapy in recent ten years

To analyze the characteristics of acupoint catgut embedding methods, tools, catgut types, and the treatment cycles in the clinical research in recent ten years both at home and abroad, so as to summarize its regularities and to provide technical references for further studies. Articles about clinical researches on catgut embedding therapy published in recent ten years (from January 1, 2010 to December 31,2020) were retrieved from the databases of CNKI, Wanfang, VIP, and PubMed by using key words of "acupoint embedding" "acupoint catgut embedding" and "catgut implantation at acupoint". According to the inclusion and exclusion criteria, a new database was established for analyzing the data mentioned above. 1) A total of 1 196 articles were collected, including 15 English articles and 1 181 Chinese articles, presenting a fluctuating increasing trend in recent ten years. 2) The commonly used acupoint embedding methods included disposable catgut embedment needle method (399 times, 38.89%) and disposable syringe needle catgut embedding method (347 times, 33.82%), for which two or multiple methods were mentioned in the same one article. 3) The most frequently used top two tools for catgut embedding were the dispo-sable catgut embedment needle (463 times, 43.03%) and disposable syringe needle (406 times,37.73%), with a significant increase in the application of disposable syringe needle. The most commonly used size of tools included No. 7 (283 times, 39.86%), No. 9 (196 times, 27.61%) and No. 8 (109 times, 15.35%). 4) The most frequently implanted surgical suture was still the common catgut (671 times, 58.15%) despite of a reduction in clinical application year by year, and the types of the implanted suture materials were gradually enriched since 2018, such as the absorbable surgical suture, polyethylprolactide(PGLA), collagen protein thread, polydioxanone(PPDO), etc. The commonly used implanted catgut size was 3-0 (227 times, 30.15%), 2-0 (176 times, 23.37%), 4-0 (131 times, 17.40%), 0 (103 times, 13.68%), with the commonly used catgut length being 1 cm (332 times, 35.55%), 1.5 cm (103 times, 11.03%), 1-2 cm (92 times, 9.85%) and 2 cm (92 times, 9.85%). 5) The intervals of the catgut implantation were 7 days (313 times, 28.95%), 14 days (262 times, 24.24%), 10 days (174 times, 16.10%), and 15 days (162 times, 14.99%). In recent ten years, clinical research on acupoint catgut embedding is growing rapidly, and the embedding methods, tools, implanted sutures, and embedding intervals are various, which may provide certain technical references for the future researches and suggest an urgent need of formulation of the standardized and unified standards in this field.

First Report of Colletotrichum fioriniae Causing Anthracnose on Rhododendron delavayi in China.

Rhododendron delavayi Franch, a member of Ericaceae family, is globally famous for its garden flowers with significant ornamental value (Liu et al., 2020). In July 2020 and 2021, a disease survey of R. delavayi groves was conducted in Baili Azalea Forest Area (N27°10'-27°20', E 105°04'-106°04'). We arbitrarily selected an area with around 280 R. delavayi trees covering 2.5 hectares in R. delavayi grove where 20-35% of leaves showed symptoms of anthracnose. Typical symptoms included elliptical to irregularly shaped brown lesions on leaves and masses of black dots clustered on it. About 30 pieces of leaves with anthracnose lesions were collected. A few black dots were picked from the lesions with a sterilized needle, plated on water agar and incubated at 25℃ for 12 h to observe spore germination (Fang, 2007). Then the germinated spores were transferred onto PDA medium for further purification and morphological observation. Fourteen single-spore isolates with similar morphology were obtained. The surface of the colony was white or gray and spongy; the edge was smooth; and the back side was pinkish brown after 7 days of growth on PDA. Conidia were spindle-shaped, transparent, 11.1-16.6×3.6-4.9 μm (n=50). Appressorium from conidia was nearly ovate or proximate, brown or dark brown in color, 4.3-10.3 ×3.2-7.6 μm (n=50). These characteristics are consistent with Colletotrichum fioriniae reported by Shivas and Tan (2009). DNA was extracted from a representative isolate MYDJ12. The internal transcribed spacer region (ITS), the glyceraldehyde-3-phosphate dehydrogenase (GAPDH), β-tubulin (TUB), actin (ACT), and chitin synthase 1 (CHS-1) genes were amplified using primer pairs described by Damm et al. (2012). The sequences were deposited in GenBank with accession number MW692854 (ITS), MW727518 (GAPDH), MW727519 (TUB2), MW727520 (ACT), and MW727521 (CHS-1). BLASTN searches of the ITS, GADPH, TUB2, ACT and CHS-1 genes revealed 100% (540/540 nucleotides), 100% (254/254 nucleotides), 99.38% (4488/491 nucleotides), 98.77% (242/245 nucleotides) and 100% (282/282 nucleotides) homology with those of C. fioriniae CBS:128517T in GenBank (NR_111747, JQ948622, JQ949943, JQ949613 and JQ948953 respectively). The phylogenetic tree showed the isolate MYDJ12 to cluster with C. fioriniae CBS:128517T. Finally, two-year old R. delavayi plants (n=5) were inoculated by wounding with a syringe needle and placing 10 μL of spore suspension (106 spores per mL) of the isolate MYDJ12 on three leaves per plant. Control leaves were inoculated with sterile water. The experiment was conducted twice. Inoculated leaves were wrapped in parafilm tape and then the plants were placed in a greenhouse at 25°C with high relative humidity (90 to 95%). Seven days after incubation, brown lesions appeared, similar to those observed in the grove. Black dots clustered on the lesions after 15 days. Re-isolation was conducted 20 days after inoculation. From all the five inoculated plants, similar symptoms were observed, and the same pathogen was re-isolated. One of the isolates was selected for morphological observation and multi-gene (ITS, GAPDH, ACT, TUB2 and CHS-1) analysis indicated the reisolated fungus to be C. fioriniae. No fungal pathogens were isolated from mock inoculated plants. This study can provide effective management and useful information for the control of this disease on R. delavayi in Baili Azalea Forest Area.

C. elegans Gonad Dissection and Freeze Crack for Immunofluorescence and DAPI Staining.

The C. elegans germline makes an excellent model for studying meiosis, in part due to the ease of conducting cytological analyses on dissected animals. Whole mount preparations preserve the structure of meiotic nuclei, and importantly, each gonad arm contains all stages of meiosis, organized in a temporal-spatial progression that makes it easy to identify nuclei at different stages. Adult hermaphrodites have two gonad arms, each organized as a closed tube with proliferating germline stem cells at the distal closed end and cellularized oocytes at the proximal open end, which join in the center at the uterus. Dissection releases one or both gonad arms from the body cavity, allowing the entirety of meiosis to be visualized. Here, a common protocol for immunofluorescence against a protein of interest is presented, followed by DAPI staining to mark all chromosomes. Young adults are immobilized in levamisole and quickly dissected using two syringe needles. After germline extrusion, the sample is fixed before undergoing a freeze crack in liquid nitrogen, which helps permeabilize the cuticle and other tissues. The sample can then be dehydrated in ethanol, rehydrated, and incubated with primary and secondary antibodies. DAPI is added to the sample in the mounting medium, which allows reliable visualization of DNA and makes it easy to find animals to image under a fluorescent microscope. This technique is readily adopted by those familiar with handling C. elegans after a few hours spent practicing the dissection method itself. This protocol has been taught to high-schoolers and undergraduates working in a research lab and incorporated into a course-based undergraduate research experience at a liberal arts college.

Comparative Study Assessing the Canal Cleanliness Using Automated Device and Conventional Syringe Needle for Root Canal Irrigation-An Ex-Vivo Study.

The success of endodontic treatment relies on both apical and coronal sealing. To achieve a good three-dimensional seal, the removal of the smear layer becomes mandatory. This study aims to assess the difference in debris accumulation and smear layer formation while using automated root canal irrigation and conventional syringe needle irrigation. Single-rooted human mandibular premolar teeth (n = 30) which were indicated for orthodontic extractions were selected. An endodontic access cavity was prepared, and a glide path was created. Based on the irrigation protocol decided upon for the study, the teeth were randomly allocated into three study groups, namely Group 1, where the manual syringe needle irrigation method was adopted; Group 2, in which automated root canal irrigation was undertaken; and Group 3, in which teeth remained un-instrumented as it was considered the Control group. The teeth were decoronated at the cement-enamel junction (CEJ) and were subjected for scanning electron microscopy (SEM) examination. Debris and smear layers were viewed in 1000× magnification and scored. A statistically significant (p < 0.05) lower mean debris and smear layer score (p < 0.05) was observed in both study groups when compared with the control group. However, no significant difference (p > 0.05) in the debris and smear layer was observed between the manual syringe needle irrigation and automated irrigation, although automated irrigation devices can be a potential alternative. The present study concluded that the efficacy of smear layer removal remained the same with both automated irrigation and manual syringe irrigation.

Analysis of flow rate and pressure in syringe-based wound irrigation using Bernoulli's equation

The objective of this study was to examine the dependence of the pressure level in the wound area on the height of the syringe needle from the wound, the gauge of the needle, and the flow rate using the Bernoulli equation. This study was the control-volume analysis using the Bernoulli equation. At a given height of the syringe needle from the wound, the gauge of the syringe needle was fixed, and the pressure in the wound area, which depended on the flow rate of the irrigation solution discharged from the tip of the needle, was calculated according to the Bernoulli equation and the definition of the flow rate. At a constant flow rate of the irrigation solution, the velocity of the irrigation solution discharged through the syringe needle decreased (7.80 → 0.80) with an increase in the diameter of the needle (18G → 14G). At a constant inner diameter of the needle, the velocity of the irrigation solution increased with a reduction in the flow rate of the solution. As the velocity of the irrigation solution increased, the pressure in the wound area increased. As the height of the syringe needle from the wound area increased, the pressure in the wound area increased. In order to maintain the pressure of 8–15 psi when nurses perform syringe-based irrigation, it is necessary to set the flow rate of the cleaning solution from 3.5 cc/s to less than 4.8 cc/s for 19G. In addition, 20G maintains the flow rate of the solution at 2.6 cc/s or more and less than 3.5 cc/s, 22G maintains the flow rate of solution at 1.3 cc/s or more and less than 1.8 cc/s, and 25G maintains the flow rate of solution at 0.5 cc/s. This study provides nurses with a reference for the flow rate at which syringe-based irrigation can be performed while maintaining the appropriate pressure based on fluid dynamics, which can be used as the basis for wound nursing standards.

Dissolution of HwBKP with [Bmim]Cl-DMF Solvent and Production of Cellulose Beads: Effect of the Cellulose Concentration and Syringe Needle Diameter

This study investigated the effects of cellulose concentration dissolved in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) and N,N-dimethylformamide (DMF) on the properties of cellulose solution and beads. Cellulose beads were prepared using the dropping method. The cellulose solution dissolved in [Bmim]Cl and DMF (mixing ratio=70:30) did not gel for 12 h and exhibited shear thinning behavior. Increasing the cellulose concentration increased the viscosity and surface tension of the cellulose solution. Cellulose beads, 600-1000 μm in size, were prepared by varying the cellulose concentration in the range of 2-4% and the syringe needle diameter in the range of 0.3-0.9 mm using the dropping method. The particle size of the beads increased with increasing cellulose concentration and diameter of the syringe needle. The cellulose concentration had no remarkable effect on the chemical structure, crystallinity, and thermal stability of cellulose.

Syringe needle-cap use as novel, static, uni-planar or bi-planar, mini-external fixator for treatment of intra-condylar phalangeal fractures

Background: Comminuted intra-articular phalanx fractures are complicated injuries often treated with external fixation. Syringe needle- cap can be an excellent mini-external fixators because they are radiolucent, readily available, inexpensive, simple, safe and easy to use. Our cases received a novel treatment in the form a syringe needle-cap/mini external fixator that was originally placed in static mode for 3 weeks and then later removed in OPD visit to a dynamic-mode of ROM to allow rehabilitation of the PIPJ/DIPJ. Our cases illustrates the power and utility of this ‘static’ uniplanar or biplanar stable technique to treat intra-condylar phalanx fractures and achieved good functional recovery of finger.Methods: This was a prospective case study covering period from January 2021 to May 2022 at department of plastic surgery, Command Hospital, Chandimandir, Panchkula, Haryana, India. 10 young male patients were presented with intra-articular fractures of phalanx. All patients had undergone pre-operative and post procedure X-rays for evaluation. A static external fixator consisting of a uniplanar or biplanar 2 ml syringe needle-cap and 0.8mm small size (3-4 cm) Kirschner wires as an optimal fixator across the fractured joint. K-wires were removed in OPD visit after 3 weeks to dynamize the ROM of affected joint of finger post-operatively.Results: 10 male patients were studied with average age of 28 years. 06 of them are intra-condylar fractures at PIP joints and rest are intra-articular fractures. After 3 weeks, we removed this fixator device and started controlled physiotherapy. End results notified in our study were achievement of good functional recovery of finger ROM at 3 months follow up.Conclusions: Syringe needle-cap use as mini-external fixation should be considered as a novel tool in the treatment of comminuted intra-articular phalangeal fracture.

Polypseudorotaxane hydrogel based on Tween 80 and α-cyclodextrin for sustained delivery of low molecular weight heparin

Low molecular weight heparin (LMWH), an anionic polysaccharide, has been widely used as a clinical anticoagulant. However, repeated subcutaneous injection is sometimes required due to its short half-life. To reduce the dosing frequency, the injectable polypseudorotaxane hydrogel was fabricated by inclusion complexation formation between Tween 80 and α-Cyclodextrin (αCD) for sustained release of LMWH. The physicochemical properties of such hydrogel were characterized by SEM, XRD, DSC, and FTIR. This hydrogel showed shear-thinning and thixotropic behavior and was easily injected through standard syringe needles. The gelation time, mechanical strength, shear viscosity, in vitro drug release rate, in vitro hydrogel dissolution rate, and in vivo hydrogel retention could be tuned by αCD concentration in the hydrogel. In vivo safety evaluation indicated that the polypseudorotaxane hydrogel was biocompatible. Most importantly, this polypseudorotaxane hydrogel could sustain release of LMWH after subcutaneous injection.