Needle Type Research Articles

Abstract P3-05-47: Regional Lymph node percutaneous analysis in patients with breast cancer

Abstract Background: The evaluation of regional lymph nodes in patients with breast cancer is one of the main predictive and prognostic factors for treatment. The most frequently methods of percutaneous evaluation for suspicious lymph nodes are fine needle aspiration (FNA) and core needle biopsy (CNB). According to the international literature, CNB and FNA are considered diagnostic methods with high specificity (98% vs. 99%), however FNA can present up to 21% of inconclusive results due to insufficient material, which leads to recall and delay in treatment approach. Although CNB is well established as a percutaneous method for the diagnostic evaluation of suspicious breast lesions, the literature is still scarce regarding the use of this method for the evaluation of suspicious regional lymph nodes in patients with breast cancer. Objectives: To analyze the results of percutaneous biopsies performed in suspected lymph nodes according to the topography and the type of needle used, and to verify the preferred method used. Methods: This was a retrospective study evaluating a public Hospital in São Paulo – Brazil (Pérola Byington Hospital database). Patients who underwent ultrasound-guided percutaneous lymph node biopsy from May 2015 to November 2017 were included. Data were analyzed and the type of biopsy (FNA or CNB) and the results were analyzed. Results: 106 medical records of patients with previous breast cancer and that underwent lymph node biopsy were reviewed. The mean age was 54.7 years (SD±12.4) in the CNB group and 54.7 years (SD±10.8) in the FNA group. Most of the patients were submitted to CNB (66% - 71 patients) and 34% were evaluated with FNA (35 patients). According to the topography of the lymph nodes, 80% were in the axilla (n=84), 10% in the supraclavicular region (n=11) and 10% in the cervical region (n=11). When analyzing the FNA results, 31% did not present sufficient material (n=11), 37% were malignant (n=13), 20% were benign (n=7) and 12% showed cellular atypia (n=12). Among the CNB performed in suspected lymph nodes, 53% were malignant (n=38) and 31% were benign (n=33), and no one had insufficient material. There were no reports of complications related to the procedures. In the insufficient material group, 27% (n=3) of the patients underwent a new percutaneous biopsy (2 CNB with malignant result and 1 FNA with inconclusive result) and 73% (8) were maintained in follow-up. The mean follow-up time was 24 months, and clinical and imaging stability was confirmed after this period. In the CNB group with malignant result, 10% (4) were diagnosed with neoplasia of other sites (cervix, lymphoma, melanoma and gastrointestinal), 78% (30) presented immunohistochemistry in agreement with that of the breast, 3% (1) presented different immunohistochemistry and in 9% (3) this evaluation was not performed. Conclusion: CNB was the preferred diagnostic method in our Hospital (66% vs 34%), being considered a viable procedure to evaluate lymph nodes in various topographies and with low rates of inconclusive results. Besides that, immunohistochemistry was done in 91% of the cases showing the importance of this analysis in the treatment of the recurrence or even in the diagnosis of other primary tumors. In the future, studies that assess indirect costs may confirm the applicability of CNB in patients with suspicious lymph nodes in terms of achieving greater agility and resolution. Citation Format: Marina Diogenes, ANDRE MATTAR, Andressa Amorim, Maria Isabela Caldas Sawada, Luiz Henrique Gebrim, Jorge Shida. Regional Lymph node percutaneous analysis in patients with breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-47.

Liver cirrhosis and tumor location can affect the range of intrahepatic microwave ablation zone

Background The range of an ablation zone (AZ) plays a crucial role in the treatment effect of microwave ablation (MWA). The aim of this study was to analyze the factors influencing the AZ range. Methods Fourteen factors in four areas were included: patient-related factors (sex, age), disease-related factors (tumor location, liver cirrhosis), serological factors (ALT, AST, total protein, albumin, total bilirubin, direct bilirubin, and platelets), and MWA parameters (ablation time, power, and needle type). Multiple sequence MRI was used to delineate AZ by three radiologists using 3D Slicer. MATLAB was used to calculate the AZ length, width, and area of the largest section. Linear regression analysis was used to analyze influencing factors. Moreover, a subgroup analysis was conducted for patients with viral hepatitis. Result 220 patients with 290 tumors were included between 2010–2021. In addition to MWA parameters, cirrhosis and tumor location were significant factors that influenced AZ (p < 0.001). The standardized coefficient (beta) of cirrhosis (cirrhosis vs. non-cirrhosis) was positive, which meant cirrhosis would lead to a decrease in AZ range. The beta of tumor location (near the hepatic hilar zone, intermediate zone, and periphery zone) was negative, indicating that AZ range decreased as the tumor location approached the hepatic hilum. For viral hepatitis patients, Fibrosis 4 (FIB4) score was a significant factor influencing AZ (p < 0.001), and the beta was negative, indicating that AZ range decreased as FIB4 increased. Conclusion Liver cirrhosis, tumor location, and FIB4 affect the AZ range and should be considered when planning MWA parameters.

Cauda Equina Syndrome and Spinal and Epidural Anesthesia. The Influence of Local Anesthetic, Needle Type and Position of Puncture

Background and Objectives: Severe complications such as Cauda Equina Syndrome (CES) lead to temporary or permanent disability have been ascribed to central neuraxial blocks. Some case reports, and very few retrospective studies, have focused their attention on the fact that central nerve blocks can cause, albeit rarely, permanent damage to the spinal cord or nerve roots, or both. This study is the experience of 48 years with spinal anesthesia and several publications and no definite neurological complications. This study is not a review of the subject. The primary objective of this study was to analyze the characteristics in relation to needles, puncture position, types of anesthetics, and baricity of local anesthetics.

Abstract No. 242 Distribution of Imageable Thermosensitive Drug-Loaded Gel in Ex Vivo Bovine Liver Depends on Needle Type and Injection Technique

Abstract No. 242 Distribution of Imageable Thermosensitive Drug-Loaded Gel in Ex Vivo Bovine Liver Depends on Needle Type and Injection Technique

Numerical Simulation of Icing Characteristics on the Surface of an Aero-engine Guide Blade

This paper takes the guiding blade of a type of aero-engine needle as the research object for the icing problem of the guiding blade and uses the numerical simulation method to simulate the airflow field, supercooled water droplet impact and icing situation on the surface of the guiding blade under different flight conditions, to analyze the influence of flight speed on the icing situation of the guiding blade. It is found that the incoming flow velocity has a significant effect on the icing of the guide vanes, with the flight velocity increasing from 34m/s to 102m/s, the icing of the leading edge of the vanes increases by 98.1%; meanwhile, the icing range of the guide vanes is significantly related to the incoming flow velocity, with the flight velocity increasing, the icing range expands significantly; in addition, the icing range gradually expands from the root to the outermost end of the vanes, with the flow velocity The maximum icing range at 102m/s was extended from 17% to 20% of the chord length.

Quincke versus Diamond-Tip Needles for Entry in Placental Laser Surgery for Twin-to-Twin Transfusion Syndrome.

Chorioamniotic membrane separation (CAS), preterm prelabor rupture of membranes (PPROM), and preterm delivery (PTD) remain as major complications of fetoscopic laser photocoagulation (FLP) for twin-to-twin transfusion syndrome (TTTS). We sought to examine whether use of Quincke-tip needles for initial entry during FLP reduces the risk of these complications. This is a secondary analysis of prospectively collected data from patients that had FLP for TTTS at a single tertiary care center (2011-2021). We excluded patients for whom direct trocar entry was used. Patients for whom a Quincke-tip needle was used were compared to those for whom a diamond-tip needle was used during Seldinger entry. Demographics, ultrasound findings and operative characteristics were compared between groups. Postoperative outcomes and complications (including CAS, PPROM, and PTD) were also compared. Multivariate logistic regression models were fit to assess independent risk factors for complications. 386 patients met inclusion criteria; Quincke-tip needles were used in 81 (21.0%) cases, while diamond-tip needles were used in 305 (79.0%). Rates of CAS (11.1 vs. 9.5%, p = 0.67) and PPROM (44.4 vs. 41.0%, p = 0.57) were similar between groups. Patients in the Quincke-tip group delivered 1.5 weeks earlier than those in the diamond-tip group (30.5 vs. 32.0 weeks, p = 0.01). However, these patients were more likely to be delivered for maternal (35.9 vs. 19.0%) and fetal (23.1 vs. 15.3%) indications (p &lt; 0.01). In multivariate analysis, needle type was not identified as an independent risk factor for PPROM. However, Quincke-tip needle use was associated with PTD less than 32 weeks (aOR 1.74, 95% CI: 1.02-2.97, p = 0.043). Membrane complications following FLP were not associated with the needle type used for entry. Earlier delivery in the Quincke-tip group was likely attributable to higher rates of delivery for maternal and fetal indications, and not membrane complications. The needle chosen for entry is likely best determined by operator preference.

Objective evaluation of the resistance forces of 22-gauge EUS-FNA and fine-needle biopsy needles.

EUS-guided tissue acquisition is routinely performed for the diagnosis of gastrointestinal tract and adjacent organ lesions. Recently, various types of needles have been developed. However, how the shape of the needle tip and echoendoscope tip angle affect puncturability, has not been clarified. The aim of this experimental study was to compare the puncturability of several 22-gauge EUS-FNA and EUS-guided fine-needle biopsy (EUS-FNB) needles, and to evaluate the effects of the needle tip shape and echoendoscope tip angle on tissue puncturability. The following six major FNA and FNB needles were evaluated: SonoTip® ProControl, EZ Shot 3 Plus, Expect™ Standard Handle, SonoTip® TopGain, Acquire™, and SharkCore™. The mean maximum resistance force against needle advancement was evaluated and compared under several conditions using an echoendoscope. The mean maximum resistance force of the needle alone was higher for the FNB needles than for the FNA needles. The mean maximum resistance force of the needle in the echoendoscope with free angle demonstrated that the resistance forces were between 2.10 and 2.34 Newton (N). The mean maximum resistance force increased upon increases in angle of the tip of echoendoscope, particularly in the FNA needles. Among the FNB needles, SharkCore™ had the lowest resistance force (2.23 N). The mean maximum resistance force of the needle alone, the needle in the echoendoscope with free angle, and the needle in the echoendoscope with full-up angle for SonoTip® TopGain were all similar to that of Acquire™. SonoTip® TopGain had similar puncturability to Acquire™ in all tested situations. Regarding the puncturability, SharkCore™ is most suitable for insertion into target lesions, when tight echoendoscope tip angle is necessary.

Bending 30-gauge needles using a needle guide: fatigue life evaluation.

Dentists bend needles prior to certain injections; however, there are concerns regarding needle fracture, lumen occlusion, and sharps handling. A previous study found that a 30-gauge needle fractures after four to nine 90° bends. This fatigue life study evaluated how many 90° bends a 30-gauge dental needle will sustain before fracture when bent using a needle guide. Two operators at Element Materials Technology, an independent testing, inspection, and certification company tested 48 30-gauge needles. After applying the needle guide, the operators bent the needle to a 90° angle and expressed the anesthetic from the tip. The needle was then bent back to a 0° angle, and the functionality was tested again. This process was repeated until the anesthetic failed to pass through the end of the needle due to fracture or obstruction. Each operator tested 24 needles (12 needles from each lot), and the number of sustained bends before the needle fracture was recorded. The average number of sustained bends before needle failure was 40.33 (95% confidence interval = 37.41-43.26), with a minimum of 20, median of 40, and a maximum of 54. In each trial, the lumen remained patent until the needle fractured. The difference between the operators was statistically significant (P < 0.001). No significant differences in performance between needle lots were observed (P = 0.504). Our results suggest that using a needle guide increases the number of sustained bends before needle fracture (P < 0.000001) than those reported in previous studies. Future studies should further evaluate the use of needle guides with other needle types across a variety of operators. Furthermore, additional opportunities lie in exploring workplace safety considerations and clinical applications of anesthetic delivery using a bent needle.

Evaluation of non-modifiable factors associated with post-dural puncture headache following subarachnoid block utilising 26 G quincke spinal needle: Prospective, observational study

Background and Aims: Post-dural puncture headache (PDPH) is one of the complications of the subarachnoid block (SAB), and the incidence of PDPH is influenced by various factors related to either patients or the type of spinal needle used. This study observed the incidence and severity of PDPH in relation to non-modifiable factors in the patients scheduled for surgeries under SAB. Methods: The study enrolled 302 obstetric and non-obstetric patients, aged 20–60 years, American Society of Anesthesiologists (ASA) I/II having body mass index (BMI) 18.5–29.9 kg.m-2 scheduled for surgeries under SAB utilizing 26 G Quincke spinal needle. Primary outcome was the incidence of PDPH in obstetric and non-obstetric patients. The secondary outcomes included onset, severity of PDPH, and association of age, BMI, and gender to PDPH. Results: The total incidence of PDPH was 5.6%, eight (7%) patients in obstetric and nine (4.8%) patients in non-obstetric group (P = 0.597). The onset of PDPH was comparable in obstetric 17.25 ± 3.69 and non-obstetric patients 18.0 ± 6.02 h (P = 0.663). None of the patient had severe PDPH. The BMI of the patients was not associated with the incidence of PDPH. The female patients among non-obstetric group had higher incidence of PDPH (P = 0.0002). The six patients having PDPH in non-obstetric group belonged to age-group of 31–40 yrs as compared to two above 40 years (P = 0.0173). Conclusion: Obstetric population had comparable incidence of PDPH to non-obstetric population. In the subgroup analysis of non-obstetric patients, the higher incidence of PDPH was observed in the female and younger patients.

Transesophageal endoscopic ultrasound-guided tissue acquisition of lung masses: a case series with systematic review and meta-analysis.

The diagnosis of intraparenchymal lung masses is challenging when lesions are located at sites inaccessible through bronchoscopy or endobronchial ultrasound. Endoscopic ultrasound (EUS)-guided tissue acquisition (TA)-fine-needle aspiration (FNA) or fine-needle biopsy-provides a potentially useful diagnostic tool for lesions located adjacent to the esophagus. This study was conducted to analyze the diagnostic outcome and safety of EUS-guided tissue sampling of lung masses. Data were retrieved for patients who underwent transesophageal EUS-guided TA between May 2020 and July 2022 at 2 tertiary care centers. A meta-analysis was performed after pooling these data with studies obtained from a comprehensive search of Medline, Embase, and ScienceDirect from January 2000 to May 2022. Pooled event rates across studies were expressed with summative statistics. After screening, 19 studies were identified and, after their data had been combined with those of 14 patients from our centers, a total of 640 patients were included in the analysis. The pooled rate of sample adequacy was 95.4% (95% confidence interval [CI] 93.1-97.8), while the pooled rate of diagnostic accuracy was 93.4% (95%CI 90.7-96.1). The pooled rate of adverse events with transesophageal EUS-guided TA from lung masses was 0.7% (95%CI 0.0-1.6%). There was no significant heterogeneity with respect to various outcomes and results were comparable on sensitivity analysis. EUS-FNA offers a safe and accurate diagnostic modality for the diagnosis of paraesophageal lung masses. Future studies are needed to determine the needle type and techniques for improving outcomes.

Comparison of the Use of Peripheral Nerve Stimulator and Quincke Needle for Lumbar Transforaminal Epidural Steroid Injections.

To compare the procedural features of transforaminal epidural steroid injection (TFESI) performed using two different needles (Stimuplex® and Quincke) in terms of procedure time, exposed radiation dose and adverse effects and complications, thus providing preliminary data to aid needle selection for TFESI. Patients who received fluoroscopy-guided single-level lumbosacral TFESI between September 2020 and September 2021 were retrospectively included in this study. The patients were divided into two groups with respect to the needle type used for the procedure ? those treated with a Quincke needle were classified as Group Q and those treated with a Stimuplex® needle comprised Group S. Subsequently, the two groups were compared in terms of their demographic data, procedure time, radiation dose, amount of contrast use, first-hour numeric rating scale (NRS), intravascular flow and complication rates. The number of patients recruited for Groups Q and S was 65 and 61, respectively. No significant difference was observed between the groups regarding their demographic data, preprocedural NRS scores, procedure time, exposed radiation dose and the amount of contrast dye used. Notably, the first-hour NRS scores were found to be significantly lower in Group S (p=0.040) after the procedure. Moreover, the intravascular contrast spread was significantly different between the two groups (p < 0.05) ? it was encountered during four procedures in Group Q, but was altogether absent in Group S. The Stimuplex® needle may decrease the possibility of inadvertent intravascular leakages during TFESI and may also improve immediate pain scores after the procedure.

Role of endoscopic ultrasound-guided tissue acquisition for the diagnosis of gastric wall thickening: a retrospective study with meta-analysis.

Tissue acquisition from a thickened gastric wall using biopsy forceps may not always lead to diagnosis, given the submucosal location of the pathology. Endoscopic ultrasound (EUS)-guided tissue acquisition (TA) may serve as a minimally invasive diagnostic tool in such cases. Hence, we aimed to assess the diagnostic outcome and safety of EUS-TA from thickened gastric walls. Data from patients with gastric wall thickening undergoing EUS-TA at 5 tertiary care centers from August 2020 to August 2022 were retrospectively analyzed. These data were pooled with studies obtained from a comprehensive search of Medline, Embase and Scopus from January 2000 to November 2022 and a meta-analysis was performed. Pooled event rates were calculated using an inverse variance model. The search strategy yielded 13 studies that were combined with data from 30 patients from our centers; a total of 399 patients were included in the analysis. The pooled rate of sample adequacy was 94.1% (95% confidence interval [CI] 90.0-98.2), while the pooled rate of diagnostic accuracy was 91.3% (95%CI 87.0-95.5). The pooled sensitivity and specificity for diagnosing malignant lesions with EUS-TA from gastric wall thickening were 94.8% (95%CI 91.3-97.2) and 100% (95%CI 93.6-100), respectively. There were no reported adverse events in any of the studies. EUS-TA offers a safe and accurate diagnostic modality for the etiological diagnosis of thickened gastric walls. Further research is required to identify the needle type and optimal technique for improving outcomes.

How to Perform Endoscopic Ultrasound-Guided Fine Needle Aspiration/Biopsy of Pancreatic Lesions?

A endoscopic ultrasound-guided fine needle aspiration/biopsy (EUS-FNA/B) of pancreatic solid and cystic lesions is a modality, which huge numbers of articles has showed its high diagnostic accuracy. The degree of technical difficulty, size and type of needle, endoscopic technique, use of suction to aspirate tissue, use or not use of a stylet in the needle assembly, maneuvers to have high quality tissue, availability of an on-site cytopathologist, and, finally, end sonographer’s experience and skills who does the procedure have impact on the EUS-FNA results. Standard 19-G and 22-G fine-needle aspiration needles with or without high negative pressure have proven to be reliable in obtaining high-quality histologic samples in various indications. Twenty-five-gauge (25-gauge) needles provide better diagnostic yield when sampling pancreatic lesions compared with 22-G needles. The novel 19-G and 22-G ProCore™ needles have demonstrated a high yield in obtaining histologic samples, whereas 25-G. ProCore™ seems unsuitable for histology. A cytopathology service should be involved early in the planning process for establishing an EUS-FNA service. Data on the newly developed 20-G ProCore™, SharkCore® and Acquire® needles are limited, but appear very promising. Use of the stylet does not increase the yield of endoscopic ultrasonography-fine-needle aspiration and is more cumbersome to use. In perspective, endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is expected to refine differential diagnostic capabilities, favor widespread EUS utilization, and pave the road to targeted therapies and monitoring of treatment response. Approximately 3 to 5 passes should be sufficient to obtain a diagnosis. We need further studies for assessment of the use of Suction, Capillary (“Slow-Pull”), Wet and Fanning techniques.

The Effect of Interrupted Homogenization on β-Al5FeSi → α-Alx (Fe and Mn) Si Transformation in the A6063 Aluminum Alloy

The aluminum alloys corresponding to the 6000 series are mainly manufactured by mechanical forming processes. Their properties are enhanced by the homogeneous distribution of intermetallic phases such as β-Al5FeSi or α-Alx (Fe, Mn) Si. By thermal homogenization treatment, the intermetallic compound β-Al5FeSi changes its morphology from a needle type with a monoclinic structure to an acicular form known as α-Al12(Fe, Mn)3Si with an fcc structure. In the present study, samples of the 6063 alloy were subjected to different temperatures of homogenization (798, 823, and 848 K) and treatment times from 0 to 660 min (in intervals of 30 min) to evaluate their effects on the microstructures and morphologies of the intermetallic phases. For the kinetic study, the microstructures of the β and α intermetallic phases were quantified using the Image-Pro software. The results indicate that as the temperature and homogenization time increase, the percentage of phase α also increments. The results of the kinetic analysis revealed that the β → α transformation is controlled by two stages; the first corresponds to the diffusion of Mn atoms from the matrix to the interface of reaction for the formation of the intermetallic phases, while the second corresponds to the nucleation and growth of the iron- and manganese-rich intermetallic phases.

Atraumatic spinal needle indicates correct CSF opening pressure

The accurate assessment of cerebrospinal fluid opening pressure during spinal puncture provides important medical information in diagnosis, prognosis and therapy of several neurological conditions. However, purpose-specific spinal needle choice is debated. While atraumatic needles are associated with lower incidence of post-puncture headache and re-hospitalisation, some clinicians believe that they lack in accuracy of CSF opening pressure assessment. Our primary objective was to investigate different needle types on correctly assessing CSF opening pressure. We compared typical clinically utilised traumatic (0.9 mm outer diameter) and atraumatic (0.7 mm; 0.45 mm) spinal needles with regards to the assessment of the opening pressure in an experimental spinal puncture model testing experimental and cerebrospinal fluids in predefined pressures. Our goal was to measure the time until indicated pressure levels were correctly shown. Atraumatic needles of at least 0.7 mm diameter had a similar accuracy as traumatic needles without significant differences in time-to-equilibrium. These results were independent of protein and glucose concentration and the presence of haemoglobin. This study demonstrates that atraumatic needles can be used to accurately measure CSF opening pressure. This knowledge might guide clinicians in their choice of needle and help to reduce post-puncture headaches and re-hospitalisation.

Intratympanic Substance Distribution After Injection of Liquid and Thermosensitive Drug Carriers: An Endoscopic Study.

In the treatment of inner ear conditions, intratympanic injection emerges as an important drug delivery method. Novel compounds designed for intratympanic injection are routinely loaded in viscous drug carriers. To date, it is unclear if they can freely distribute in the middle ear. The aims of this study were to investigate the middle ear distribution of different drug carriers during intratympanic injection and to determine an optimal injection method for thermosensitive hydrogels. Twenty-one human temporal bones were intratympanically injected with fluid drug carriers or poloxamer-407 hydrogels at different tympanic membrane injection sites (inferior, anterior-superior) using different needle types (Whitacre, Quincke). Fluid distribution was evaluated via an endoscopic view. Injection volume, duration, backflow, and overall safety were analyzed. Liquid drug carriers distribute effortlessly in the middle ear, whereas an additional ventilation hole is advantageous when applying thermosensitive hydrogels. The round window is coated with required volumes between 150 and 200 μl, irrespective of the injection position. Required volumes to also coat the stapedial footplate ranged from 310 to 440 μl. Use of the Whitacre-type needle reduced backflow to the ear canal and enabled longer tympanic membrane visibility when no additional ventilation hole was placed. Intratympanic injection is a safe and reliable method for the application of thermosensitive hydrogels. The round window niche is readily filled regardless of the injected formulation and injection position. Although fluid drug carriers distribute effortlessly in the middle ear, the placement of an additional ventilation hole might facilitate the application of viscous hydrogels.

Actual pressure generated by various suction technique and suctioning liquid weight through endoscopic ultrasound-guided aspiration needles.

Suction pressure is one of the most important factors influencing the amount of tissue obtained during endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/FNB). In this study we aimed to elucidate actual suction pressure generated by various suction methods and the weight of suctioning liquid. Different types of fine needles and suction techniques were used, including the slow pull technique (SPT), dry suction technique (DST), wet suction technique (WST), neutralizing negative pressure technique (NNPT), and residual negative pressure technique (RNPT). Actual suction pressure was measured and the amount of suctioning liquid was weighed. Actual suction pressure and weight of the suctioning liquid were lower using SPT than using DST, while they were higher when using WST compared with those using DST. In general, the actual suction pressure increased and the weight of suctioning liquid decreased as the diameter of the FNA needles decreased. While weight of the suctioning liquid using FNB needles was significantly larger than that using FNA needles. In general, the actual suction pressure generated using RNPT was larger than that using NNPT. WST is superior to SPT and DST in terms of actual suction pressure and weight of suctioning liquid. Diameter of the FNA needle was an important factor that may affect the actual suction pressure and weight of suctioning liquid. FNB needles are superior to FNA needles when it comes to the weight of suctioning liquid. Actual suction pressure obtained by novel suction methods (NNPT and RNPT) may provide a basis for future research.

Microstructure and tensile properties of bulk AISI D2 tool steel fabricated by direct energy deposition

This study investigated the microstructure and tensile properties of AISI D2 tool steel manufactured by direct energy deposition (DED). The effect of standard post-heat treatment on the mechanical properties and deformation behavior of DED AISI D2 was also examined. The as-built AISI D2 manufactured through the DED process showed the eutectic structure in the interdendrite area in addition to dendrites about 4–5 μm wide. After heat treatment, the carbides in eutectic lamellar structure were transformed into the network and needle type secondary carbides. The DED-built material was interestingly composed of austenite, which transformed into martensite after heat treatment. Hardness value for DED-built material was 486.2 ± 10.6 HV, while for heat-treated material the value was 720.1 ± 10.0 HV. Furthermore, post heat treatment led to tremendous increases in yield strength (784 ± 7.7 MPa to 1480 ± 43.0 MPa) and tensile strength (1054 ± 2 MPa to 1794 ± 69.0 MPa). The hardness value, yield and tensile strengths for DED-built AISI D2 were similar to those of heat-treated conventional wrought AISI D2. In addition, brittle fractures were observed in the tensile fracture surfaces regardless of whether heat treatment was applied. In particular, tensile deformed specimen before heat treatment showed deformation-induced martensite transformation in the areas close to the eutectic structures, while after heat treatment interdendritic cracking as well as transdendritic cracking within the matrix were mainly detected. Based on the above results, the deformation behavior and fracture mechanism of AISI D2 manufactured by direct energy deposition were also discussed.

Characterization and single track analysis of a metal-ceramic composite laser cladding over Ti6Al4V alloy

The present experimental investigation is dealt with the formation of composite cladding on Ti6Al4V alloy using laser melting and deposition (LMD) technique. The reinforcement consisting of ilmenite (Fe-TiO3), CeO2, La2O3, cubic boron nitride (cBN) and Ti6Al4V in different compositions ratio are considered as cladding materials to fabricate a dense composite clad surface. Single tracks are formed using 15.92 × 104 w/cm2 laser power density and three different laser scanning speeds of 200,400 and 600 mm/min to analyze the clad height, aspect ratio, dilution rate and average contact angle of the track. Further, area clads are fabricated for different powder compositions of the cladding materials. The clad layer thickness are found to be decreases with increase in laser scanning speed and rise in the percentage of ilmenite (Fe-TiO3). The formation of different microstructure in the clad as well as interface zone are observed. With the increase in the percentage composition of ilmenite with cerium and lanthanum leads to the refined and coarser grain microstructure with unique structure are found which enhance mechanical properties like wear and hardness of the clad. Some of the important microstructure like dendritic, lamellar, flower, grit type and long needle type are found on the clad surface. The formation of unique chemical compound such as Ti3O, La2O3, Ti2B5, LaTi21O38, Ce3B2N4, Fe4N, TiN, La3BO6, and Fe-TiO3 are observed through the XRD analysis. Micro hardness of the clad surface are found to be increases approximately five times to the substrate at the clad with the increase in percentage composition of RE element, but found to be decrease drastically as passing through the intersection zone due to intermixing phenomena of clad and the substrate. It is observed that with higher percentage composition of RE result decrease in the reduction of the coefficient of friction approximately thrice to that of the cladded sample as compare to base (Ti6Al4V), which improve the wear resistance of the clad material. However there are minor amount of defects like micro crack are found on the clad and wear at the disk are occurred due to ploughing and cutting observed through track analysis.

Does follicular flushing increase oocyte number in poor responders? An update of a systematic review

Research questionDoes flushing of the follicles at ovum retrieval increase the number of retrieved oocytes in poor-response IVF patients? DesignAn update of an electronic literature search was performed to identify randomized controlled trials (RCT) investigating follicular flushing versus no flushing in women with a poor response to IVF treatment. No exclusion criteria for type of needle, stimulation or protocol were applied. A meta-analysis was conducted using the software RevMan 5.4. ResultsSix RCT were identified that had the primary objective of testing for an increase in mean number of cumulus–oocyte complexes or/and metaphase II oocytes between flushing and no flushing. A double-lumen needle was used in five trials, one study investigated a pseudo-double-lumen needle, and a conventional single-lumen needle was used in all the control groups. The main risk of bias in all the included studies is a lack of blinding of the physicians performing the puncture and incomplete data in four trials. A heterogeneity of direction and size of effect of follicular flushing on mean oocyte number retrieved was detected (I2 = 80, P = 0.0001), which precludes a synthesis of the data. Two studies showed a decrease or tendency towards a decrease in oocyte numbers, one study showed similar oocyte numbers, and one study showed a strong tendency towards increased oocyte numbers with flushing. A similar picture was seen for metaphase II oocytes (I2 = 73, P = 0.002). ConclusionsIt is uncertain whether follicular flushing in poor-response IVF patients affects the number of retrieved oocytes. Larger pragmatic trials are warranted to clarify the effect of flushing on oocyte numbers and clinical outcomes in poor responders and monofollicular patients.