Coupling Gel Research Articles

Ultrasonographic approach to visualize the medial shoulder compartment and diagnose medial glenohumeral ligament and subscapularis lesions in dogs.

To provide a video tutorial on the diagnostic ultrasound approach to the medial compartment of the canine shoulder and provide comparisons of normal and pathological images with corresponding MRI. Dogs undergoing diagnostic ultrasound of the medial shoulder. The medial shoulder was positioned in flexion with external rotation to allow transducer access, clipped, and scrubbed with dilute chlorhexidine. A 2- to 14-MHz linear array probe with a footprint of 50 mm (V8 ultrasound system; Samsung) was used to visualize the medial glenohumeral ligament (MGL), subscapularis, and coracobrachialis with coupling gel, confirmed by cadaveric ultrasound-guided dye injection and dissection. Ultrasound and corresponding MRI were then used to contrast normal anatomy to a live sedated dog with clinical subscapularis tendinopathy and MGL desmopathy. Proton density-weighted MRI sequences (1.5T Vantage Orian; Canon) using a flex coil were able to identify all 3 structures and corresponded to ultrasound findings for normal and pathological anatomy. Diagnostic ultrasound identified normal and abnormal structures of the medial shoulder (coracobrachialis, subscapularis, and MGL). All imaging correlated well to MRI. Medial compartment disease of the shoulder is a well-described cause of canine lameness, but diagnosis has traditionally relied on MRI or arthroscopy. Prior ultrasound approaches did not distinguish MGL components, failed to consistently identify normal or surgically transected ligaments, and have not been studied in vivo. Our approach is different and can play an important role in diagnosing medial compartment lesions, as it possesses greater anatomical visualization than arthroscopy and is noninvasive, accomplished with sedation, and relatively accessible and affordable.

Comparison of chemical, biological, physical and electrical properties between commercial ultrasound gel and Aloe vera gel

Ultrasound is an imaging diagnostic method that uses mechanical waves and requires acoustic coupling gel for the efficient transmission of ultrasonic waves. This study investigated Aloe vera gel as an alternative to the commercial gel used in ultrasound exams. The chemical, biological, electrical, and physical aspects of both gels were analyzed using Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDS), cytotoxicity assays, and conductivity tests. The Aloe vera gel contained carbon, oxygen, magnesium, calcium, and phosphorus, while the commercial gel contained only carbon and oxygen. Aloe vera was found to be safe for biological tissues, with performance equivalent to or superior to the commercial gel in ultrasound exams. This can be attributed to its lower electrical resistance and higher quantity of free ions, which reduced impedance between the transducer and the skin, facilitating the propagation of ultrasonic waves. Thus, Aloe vera gel emerges as a promising and viable alternative for ultrasound, offering biocompatibility, technical performance, and safety.

Effect of low-intensity focused ultrasound therapy on postpartum uterine involution in puerperal women: A randomized controlled trial.

Short-term poor uterine involution manifests as uterine contraction weakness. This is one of the important causes of postpartum hemorrhage, posing a serious threat to the mother's life and safety. The study aims to investigate whether low-intensity focused ultrasound (LIFUS) can effectively shorten lochia duration, alleviate postpartum complications, and accelerate uterine involution compared with the sham treatment. A multicenter, concealed, randomized, blinded, and sham-controlled clinical trial was conducted across three medical centers involving 176 subjects, utilizing a parallel group design. Enrollment occurred between October 2019 and September 2020, with a 42-day follow-up period. Participants meeting the inclusion and exclusion criteria based on normal prenatal examinations were randomly divided into the LIFUS group or the sham operation group via computer-generated randomization. Patients in the LIFUS group received usual care with the LIFUS protocol, wherein a LIFUS signal was transmitted to the uterine site through coupling gel, or sham treatment, where no low-intensity ultrasound signal output was emitted. The primary outcome, lochia duration, was assessed via weekly telephonic follow-ups post-discharge. The involution of the uterus, measured by uterine fundus height, served as the secondary outcome. Among the 256 subjects screened for eligibility, 176 subjects were enrolled and randomly assigned to either the LIFUS group (n = 88) or the Sham group (n = 88). Data on the height of the uterine fundus were obtained from all the patients, with 696 out of 704 measurements (99%) successfully recorded. Overall, a statistically significant difference was noted in time to lochia termination (hazard ratio: 2.65; 95% confidence interval [CI]: 1.82-3.85; P < 0.001). The decline in fundal height exhibited notable discrepancies between the two groups following the second treatment session (mean difference: -1.74; 95% CI: -1.23 to -2.25; P < 0.001) and the third treatment session (mean difference: -3.26; 95% CI: -2.74 to -3.78; P < 0.001) after delivery. None of the subjects had any adverse reactions, such as skin damage or allergies during the treatment. This study found that LIFUS treatment can promote uterine involution and abbreviate the duration of postpartum lochia. Ultrasound emerges as a safe and effective intervention, poised to address further clinical inquiries in the domain of postpartum rehabilitation.

Quality assurance for focused ultrasound-induced blood-brain barrier opening procedure using passive acoustic detection

Focused ultrasound (FUS) combined with microbubbles is a promising technique for noninvasive, reversible, and spatially targeted blood-brain barrier opening, with clinical trials currently ongoing. Despite the fast development of this technology, there is a lack of established quality assurance (QA) strategies to ensure procedure consistency and safety. To address this challenge, this study presents the development and clinical evaluation of a passive acoustic detection-based QA protocol for FUS-induced blood-brain barrier opening (FUS-BBBO) procedure. Ten glioma patients were recruited to a clinical trial for evaluating a neuronavigation-guided FUS device. An acoustic sensor was incorporated at the center of the FUS device to passively capture acoustic signals for accomplishing three QA functions: FUS device QA to ensure the device functions consistently, acoustic coupling QA to detect air bubbles trapped in the acoustic coupling gel and water bladder of the transducer, and FUS procedure QA to evaluate the consistency of the treatment procedure. The FUS device passed the device QA in 9/10 patient studies. 4/9 cases failed acoustic coupling QA on the first try. The acoustic coupling procedure was repeatedly performed until it passed QA in 3/4 cases. One case failed acoustic coupling QA due to time constraints. Realtime passive cavitation monitoring was performed for FUS procedure QA, which captured variations in FUS-induced microbubble cavitation dynamics among patients. This study demonstrated that the proposed passive acoustic detection could be integrated with a clinical FUS system for the QA of the FUS-BBBO procedure. National Institutes of Health R01CA276174, R01MH116981, UG3MH126861, R01EB027223, R01EB030102, and R01NS128461.

Ultrasound image quality of the carpal tunnel during a pinch grip: effects of coupling media and wrist position

ABSTRACT High quality ultrasound is required for evaluating carpal tunnel dynamics. The purpose of this study was to subjectively assess ultrasound video quality of the carpal tunnel with two commonly used coupling media (coupling gel, 7 mm standoff pad) in two wrist positions (0° neutral, 30° flexion) over the entire time course of a pinch grip. Seventeen participants completed a pinch grip while their carpal tunnel was scanned with ultrasound. The ultrasound videos were graded by two independent reviewers using 10-point scales encompassing median nerve detail, resolution, and total video quality. Intra- and inter-rater reliability were highest for median nerve detail (ICCs>.85). Ultrasound videos in the 0° neutral wrist condition resulted in significantly greater ratings of nerve detail compared to those in 30° wrist flexion. Future studies may benefit from a more customised approach to standoff pad thickness during dedicated analysis of the median nerve in a neutral wrist position.

Preliminary study of the effect of low-intensity focused ultrasound on postpartum uterine involution and breast pain in puerperal women: a randomised controlled trial

To evaluate the safety and efficacy of low-intensity focused ultrasound (LIFU) therapy in facilitating fundus descent and relieving postpartum breast pain compared with sham treatment. A multicentre, randomised, sham-controlled, blinded trial was conducted. A cohort of 176 eligible participants, who had normal prenatal check-ups and met the inclusion and exclusion criteria, were recruited from three medical centres and subsequently randomized into either the LIFU or sham group. All participants received three treatment sessions, wherein LIFU signal was applied to the uterus and breast sites using coupling gel, with the absence of ultrasound signal output in the sham group. Fundal height measurement and breast pain score were performed after each treatment. The primary outcome, uterine involution, was presented by measuring the fundal height of the uterus. The visual analogue scale (VAS) score, as a secondary outcome, was used to assess breast pain and determine the correlation between breast pain and fundal height as the outcome simultaneously. All participants were randomly assigned to either the LIFU group (n = 88) or sham group (n = 88), with seven individuals not completing the treatment. Overall, a statistically significant difference was noted in the rate and index of fundus descent after each treatment. The rate and index of fundus descent showed greater significance following the second treatment (rate: 1.5 (1.0, 2.0) cm/d; index: 0.15 (0.1, 0.18), P < 0.001) and third treatment (rate: 1.67 (1.33, 2.0) cm/d; index: 0.26 (0.23, 0.3), P < 0.001) in the LIFU group. VAS scores, which were based on the continuous variables for the baseline, first, second, and third treatments in the LIFU group (2.0 (2.0, 3.0), 1.0 (0.0, 2.0), 0.0 (0.0, 1.0), and 0.0 (0.0, 0.0) points, respectively), and the sham group (2.0 (2.0, 2.0), 2.0 (1.0, 2.0), 2.0 (1.0, 3.0), and 3.0 (1.0, 3.0) points, respectively), showed a statistically significant difference between the two groups. Meanwhile, the discrepancies in VAS score classification variables between the two groups were statistically significant. After the third treatment, a notable correlation was observed between the VAS score decrease and fundus descent rate; the more the VAS score decreased, the faster was the fundal decline rate in the LIFU group. LIFU therapy is safe and effective, contributing to the acceleration of uterine involution and the relief of postpartum breast pain.Trial ID The study has registered in the Chinese Clinical Trial Registry (ChiCTR2100049586) at 05/08/2021.

Heavy water coupling gel for short-wave infrared photoacoustic imaging.

Changes in lipid, water, and collagen (LWC) content in tissue are associated with numerous medical abnormalities (cancer, atherosclerosis, and Alzheimer's disease). Standard imaging modalities are limited in resolution, specificity, and/or penetration for quantifying these changes. Short-wave infrared (SWIR) photoacoustic imaging (PAI) has the potential to overcome these challenges by exploiting the unique optical absorption properties of . This study's aim is to harness SWIR PAI for mapping LWC changes in tissue. The focus lies in devising a reflection-mode PAI technique that surmounts current limitations related to SWIR light delivery. To enhance light delivery for reflection-mode SWIR PAI, we designed a deuterium oxide (, "heavy water") gelatin (HWG) interface for opto-acoustic coupling, intended to significantly improve light transmission above 1200nm. HWG permits light delivery up to 1850nm, which was not possible with water-based coupling ( light delivery up to 1350nm). PAI using the HWG interface and the Visualsonics Vevo LAZR-X reveals a signal increase up to 24dB at 1720nm in lipid-rich regions. By overcoming barriers related to light penetration, the HWG coupling interface enables accurate quantification/monitoring of biomarkers like LWC using reflection-mode PAI. This technological stride offers potential for tracking changes in chronic diseases (in vivo) and evaluating their responses to therapeutic interventions.

The effect of gel pads on the measurement of breast superficial lesions by shear wave elastography

Objective This study aimed to compare the repeatability and diagnostic efficiency of shear wave elastography (SWE) while using coupling gel and gel pads in the diagnosis of superficial breast lesions. Methods Two experienced sonographers, trained in SWE, used different methods to perform the maximum Young’s modulus (Emax) measurement of the lesion while using coupling gel SWE and gel pad SWE at different time points. All 80 lesions were in the superficial layer of the breast. The interclass correlation coefficient (ICC) was calculated to evaluate the intraobserver and interobserver repeatability. Meanwhile, the receiver operating characteristic curve (ROC curve) was used to calculate the sensitivity, specificity and area under the curve of the two methods. Results In the 80 breast lesions, the intraobserver and interobserver reproducibility of SWE measurements using coupling gel were considered good, and the ICCs were 0.728 (95% CI: 0.509–0.813) and 0.702 (95% CI: 0.492–0.795), respectively. The intraobserver and interobserver reproducibility of the SWE measured by the gel pad were also considered good, and the ICCs were 0.745 (95% CI: 0.501–0.801) and 0.713 (95% CI: 0.498–0.802), respectively. The sensitivity, specificity and area under the curve were 0.711 and 0.737, 0.929 and 0.905, and 0.873 and 0.878, respectively. Conclusions In the SWE measurement of superficial breast lesions, the use of a gel pad does not affect the repeatability and diagnostic efficiency of the measurement.

Effect of geometric parameters of electrodes on skin heating for the design of non-ablative radiofrequency device.

Non-ablative radiofrequency (RF) has been widely used in clinical and at-home cosmetics devices. RF electrode geometry can influence the heat distribution in the tissue. This study analyzes the influence of geometric parameters of the electrode on the heat distribution in the layered tissue. The finite element simulation of the electrothermal coupling field was performed to obtain the three-dimensional (3D) temperature distribution of the four-layer tissue. The electrode geometric parameters including the inter-electrode spacing (5-12mm), width (1-3mm), length (3-10mm), shapes (bar, dot and circle), and the coupling gel's electrical conductivity (0.2-1.5 S/m) were simulated. The maximum temperature at 2mm depth (T-2mm ) and the temperature difference (Tdiff ) between the maximum skin surface temperature and T-2mm were obtained to evaluate the effectiveness and safety. The effect of geometric parameters on the effectiveness and safety was mixed. The maximum T-2mm occurred with the 5mm inter-electrode spacing, 3mm width, 10mm length, the circle-shaped electrode, and the 1.5 S/m coupling gel's electrical conductivity. The ratio of inter-electrode spacing to width at around four can achieve rapid temperature rise and skin surface temperature protection. The electrode shape influenced the area of temperature rise in the tissue's cross-section. The coupling gel's electrical conductivity should be close to that of the skin to avoid energy accumulation on the skin surface. The electrode's geometric parameters affect the effectiveness and safety of the RF product. This study has provided the simulation procedure for the electrode design.

Lymphatic Mapping with Contrast-enhanced Ultrasound for Lymphaticovenous Anastomosis Surgery: How We Do It.

Lymphaticovenous anastomosis (LVA) surgery is an effective surgery for the treatment of lymphedema in the extremities. Indocyanine green lymphography is the reference standard for visualizing lymphatics for LVA surgery, but it has several limitations; most notably, superficial dermal congestion can mask deeper lymphatic vessels. To overcome the limitations, we add contrast-enhanced ultrasound (CEUS) lymphography. We have previously reported that CEUS lymphography can identify lymphatic vessels for LVA surgery that indocyanine green lymphography does not. Here, we describe how we perform CEUS lymphography, including workflow, technique, and documentation. Before informed consent, the patient must be screened for possible adverse reactions to microbubbles. The procedure involves multiple intradermal injections of the microbubble agent at various sites along the extremity. After each injection, imaging for microbubble uptake by lymphatic vessels is performed using an ultrasound scanner with contrast-specific software. We use sulfur hexafluoride lipid-type A microspheres (Lumason/SonoVue; Bracco Suisse SA), but we are investigating the performance of other Food & Drug Administration-approved microbubble agents for CEUS lymphography. Having a systematic approach to marking the skin can mitigate the hindrance of marking over ultrasound coupling gel. Another benefit of CEUS lymphography is the rapid identification of neighboring veins compatible in size and location for anastomosis. We hold regular scheduled multidisciplinary meetings for coordination of care, discussion of outcomes, quality assurance, and ongoing innovation.

Highly Efficient Gel Electrophoresis for Accurate Quantification of Nucleic Acid Modifications via in-Gel Digestion with UHPLC-MS/MS.

Gel electrophoresis is a powerful technique for the characterization of sequences, sizes and conformations of nucleic acids due to its remarkable separation efficiency. In parallel, liquid chromatography-mass spectrometry (LC-MS) has established itself as a staple tool for the meticulous characterization and accurate quantification of a multitude of DNA modifications. In this study, we devised an in-gel digestion method for coupling gel electrophoresis with LC-MS/MS. This process involves the enzymatic digestion of DNA within the gel by nucleases and release single nucleosides, which subsequently serve as a preprocessing step for (LC-MS/MS) analysis. We demonstrated that ethylenediaminetetraacetic acid (EDTA) in the routine gel electrophoresis buffer reduced the enzymatic digestion efficiency, while Mg2+ could mitigate this inhibition. We further showed EDTA-free gel electrophoresis and the process of digestion of genomic DNA and plasmid DNA within a gel was fluorescently imaged, proving the efficient digestion of DNA. By this improvement, the efficiency of an in-gel digestion could reach 60% or more of the control, compared with direct in-solution digestion. The measured abundances of DNA modifications (5-methylcytosine and N6-methyladenine) via in-gel digestion are consistent with that measured by in-solution digestion. Collectively, we showed an in-gel digestion method, which is a very useful pretreatment technique for the precise quantification of epigenetic modifications in diverse DNA molecules.

2D shear wave elastography for the assessment of quadriceps entheses-a methodological study.

To establish the scanning protocol for 2-dimensional shear wave elastography (SWE) on normal entheses by investigating the possible confounding factors that may increase the variability of measured elasticity. 30 normal quadriceps entheses were scanned using SWE to compare the stiffness and coefficient variation by changing the ultrasonic coupling gel thickness, knee position, region of interest size, and scanning plane. No significant difference in median shear wave velocity (SWV) was observed in different coupling gel thicknesses. The median SWV was higher in the knee flexion position than in the extended position (p < 0.001). Increased knee flexion led to stiffer quadriceps enthesis and higher SWV (ρ = 0.8, p < 0.001). The median SWV was higher when the diameter region of interest was 4.0mm than 2.0mm (p = 0.001). The median SWV was higher in the transverse plane than in the longitudinal plane (p < 0.001). Strong correlation was found between SWV and the degree of the shear wave to muscle fiber direction (ρ = 0.8, p < 0.001). The coefficient variation was lower in a gel thickness of 2.5cm, with an extended knee, a region of interest of 2.0mm, and a longitudinal plane (p > 0.05). For interobserver reliability for the proposed protocol, the intraclass correlation coefficients was 0.763. In this study, we determined supine position with the knee extended; using 2.0mm diameter region of interest and image acquisition at the longitudinal plane with thicker layer coupling gel seems most appropriate to reliably image healthy quadriceps entheses with SWE.

Factors influencing the Shear Wave Elastography evaluation of the patellar tendon.

There is no clear standardization for tendon Shear Wave Elastography (SWE), and data regarding the factors that influence the correctness of evaluation are scarce. We aimed to determine the intra- and interobserver agreement in patellar tendon SWE, and to establish the influence of various factors on elasticity values. We recruited 37 healthy volunteers; SWE of the patellar tendon was performed by two examiners. The following factors were analyzed: probe frequency, degree of joint flexion, size of region of interest (ROI), distance of the color box from the probe footprint, utilization of coupling gel as standoff, and the effect of physical exercise on elastic modulus values. Highest overall interobserver [k=0.767, 95%CI (0.717-0.799), p<0.001] and intraobserver agreement [k=0.920 (0.909-0.929) for examiner 1, k=0.891 (0.875-0.905) for examiner 2] was obtained with the knee in the neutral position, using the L18-5 probe. With the knee flexed at 30º and 45º, the elasticity values were higher compared to the neutral position (p<0.001). With the probe immersed in 0.25 and 0.50 cm coupling gel, the median values were lower compared to the probe placed on the skin (p=0.001, p=0.018). The ROI dimensions and the placement of the SWE box at the level of the skin or at 0.5 cm below skin did not significantly influence the elastic modulus. After physical exercise, the elasticity values decreased in the proximal and middle portion of the tendon (p=0.002, p<0.001). The best results obtained in patellar tendon SWE were with the knee in neutral position, in the proximal or middle tendon, after 10 minutes of relaxation and with the probe placed directly on the skin with minimal pressure. The size and position of ROI do not significantly influence the examination.

Pressure and Light Multi-Physics Fields Comodulate the Multi-Length Scales of Chemical Wave Propagation in Diffusion-Fed Gels

During plant growth, the combined effects of multi-physics fields such as light, temperature, and material concentration create a complex multi-length scales phenomenon. However, the mechanism of multi-physical field interactions on biological multi-length scales has not been thoroughly investigated. In this paper, an open diffusion-fed system is constructed by coupling gels with a Belousov-Zhabotinsky (BZ) chemical reaction system. The multi-length scales propagation of chemical waves in the gel system under the combined effect of multi-physical fields such as light (I) and pressure (ΔP) is investigated. It is found that when 85 Pa ≤ ΔP ≤ 100 Pa or 200 μW·cm-2 ≤ I ≤ 300 μW·cm-2, the complexity of the multi-length scales periodic structure of chemical waves shows a nonlinear change with increasing light intensity or pressure. Beyond this range, the complexity of the chemical wave multi-length scales periodic structure decreases linearly on enhancing the light intensity or increasing the pressure.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

AIUM Official Statement: Guidelines for Cleaning and Preparing External- and Internal-Use Ultrasound Transducers and Equipment Between Patients as Well as Safe Handling and Use of Ultrasound Coupling Gel.

AIUM Official Statement: Guidelines for Cleaning and Preparing External- and Internal-Use Ultrasound Transducers and Equipment Between Patients as Well as Safe Handling and Use of Ultrasound Coupling Gel.

Factors Associated With Ultrasound Color Doppler Twinkling by Breast Biopsy Markers: In Vitro and Ex Vivo Evaluation of 35 Commercially Available Markers.

BACKGROUND. Targeted axillary lymph node dissection after neoadjuvant systemic therapy (NST) for breast cancer depends on identifying marked metastatic lymph nodes. However, ultrasound visualization of biopsy markers is challenging. OBJECTIVE. The purpose of our study was to identify biopsy markers that show actionable twinkling in cadaveric breast and to assess the association of actionable twinkling with markers' surface roughness. METHODS. Commercial breast biopsy markers were evaluated for twinkling artifact in various experimental conditions relating to scanning medium (solid gel phantom, ultrasound coupling gel, cadaveric breast), transducer (ML6-15, 9L, C1-6), and embedding material (present vs absent). Markers were assigned twinkling scores from 0 (confident in no twinkling) to 4 (confident in exuberant twinkling); a score of 3 or greater represented actionable twinkling (sufficient confidence to rely solely on twinkling for target localization). Markers were hierarchically advanced to evaluation with increasingly complex media if showing at least minimal twinkling for a given medium. A 3D coherence optical profiler measured marker surface roughness. Mixed-effects proportional odds regression models assessed associations between twinkling scores and transducer and embedding material; Wilcoxon rank sum test evaluated associations between actionable twinkling and surface roughness. RESULTS. Thirty-five markers (21 with embedding material) were evaluated. Ten markers without embedding material advanced to evaluation in cadaveric breast. Higher twinkling scores were associated with presence of embedding material (odds ratio [OR] = 5.05 in solid gel phantom, 9.84 in coupling gel) and transducer (using the C1-6 transducer as reference; 9L transducer: OR = 0.36, 0.83, and 0.04 in solid gel phantom, ultrasound coupling gel, and cadaveric breast; ML6-15 transducer: OR = 0.07, 0.18, and 0.00 respectively; post hoc p between 9L and ML6-15: p < .001, p = .02, and p = .04). In cadaveric breast, three markers (Cork, Professional Q, MRI [Flex]) exhibited actionable twinkling for two or more transducers; surface roughness was significantly higher for markers with than without actionable twinkling for C1-6 (median values: 0.97 vs 0.35, p = .02) and 9L (1.75 vs 0.36; p = .002) transducers. CONCLUSION. Certain breast biopsy markers exhibited actionable twinkling in cadaveric breast. Twinkling was observed with greater confidence for the C1-6 and 9L transducers than the ML6-15 transducer. Actionable twinkling was associated with higher marker surface roughness. CLINICAL IMPACT. Use of twinkling for marker detection could impact preoperative or intraoperative localization after NST.

Resolving Solvent Incompatibility in Two-Dimensional Liquid Chromatography with In-Line Mixing Modulation.

Two-dimensional liquid chromatography (2D-LC) is a powerful technique used to characterize complex samples such as synthetic polymers, biomacromolecules, and hybrid modalities (conjugates, oligonucleotides, nanoparticles, etc., which fall between traditional small molecules and large molecules). Characterizing such molecules often requires a highly orthogonal 2D-LC workflow to resolve structurally similar impurities. However, it remains a challenge to achieve truly orthogonal 2D-LC coupling due to incompatibility of the chromatographic conditions used in each dimension. In this work, we present a facile strategy of connecting an in-line mixer, in-line mixing modulation (ILMM), to realize challenging 2D-LC workflows: (1) coupling gel permeation chromatography (GPC) with reversed-phase liquid chromatography (RPLC) for hydrophobic oligomer analysis and (2) coupling ion-pair reversed-phase (IPRP) with hydrophilic interaction liquid chromatography (HILIC) for polar antisense oligonucleotide (ASO) analysis. Compared with the state-of-the-art commercially available active solvent modulation (ASM), engaging the ILMM significantly reduces the peak distortion in GPC-RPLC, allowing an at least 67% higher transfer volume from the primary to secondary dimension, and resolves the ASO sample breakthrough in selective comprehensive IPRP×HILIC. Also remarkably, ILMM demonstrated superiority in comprehensive RPLC×RPLC analysis in comparison with ASM, suggesting its potential in broader 2D-LC applications. In addition to chromatography improvement, ILMM offers several advantages over benchmark modulation approaches in regard to alleviating the need of an additional dilution flow and a simple as well as flexible system configuration, opening many opportunities to establish innovative and versatile multidimensional workflows for characterizing compounds with increasing complexity.

Role of B-Scan Ultrasonography in Pre-Operative Cataract Patients Attending Services Hospital, Lahore

Aim: The present study aimed to assess the role of B-scan in pre-operative cataract patients. Material and Methods: This prospective diagnostic study was conducted on 94 cataract patients in Ophthalmology Department, Services Hospital, Lahore from January 2021 to June 2021. Patients of either gender regardless of age having cataract were enrolled. Clinical history, detailed examination, and B-scan ultrasound of each individual was recorded. Individuals were examined in a lie supine position on the table and contact method was used. Coupling gel was applied and a probe was placed on the closed eyelid. B-scan ultrasound took images of different sections such as longitudinal, axial, and transverse sections. Resolution of the images was optimized by maintaining adequate intensity with the lowest possible decibel gain. Results: Out of 94 cataract patients, the number of male and female patients was 54 (57.4%) and 40 (42.6%) respectively. The incidence of traumatic and non-traumatic cataract patients was 20 (21%) and 74 (79%) respectively. About 42 (44.7%) cataract patients had a rural background and 52 (55.3%) had an urban background. The age distribution of cataract patients was as follows: 12 (12.8%) 1-20 years, 4 (4.3%) in 21-30 years, 19 (20.2%) in 31-40 years, 21 (22.3%) in 41-50 years, 32 (34%) in 51-60 years, and 6 (6.4%) &gt;60 years. Of the traumatic cataract patients, posterior segment pathology was observed in 8 (40%) only whereas 12 (60%) had no posterior segment pathology. Out of traumatic cataract patient’s posterior segment pathology, the incidence of retinal detachment, vitreous hemorrhage, posterior vitreous detachment, intraocular foreign body and posterior staphyloma was 2 (25%), 1 (12.5%), 1 (12.5%), 3 (37.5%), and 0 (0%) respectively. Out of non-traumatic cataract patients, the incidence of posterior segment pathology and no posterior segment pathology was observed in 14 (18.9%) and 60 (81.1%) respectively. Among 14 posterior segment pathology, the incidence of retinal detachment, vitreous hemorrhage, posterior vitreous detachment, intraocular foreign body, and posterior staphyloma was 4 (28.6%), 3 (21.4%), 2 (14.3%), 2 (14.3%), and 3 (21.4%) respectively. Conclusion: The present study found that B-scan is a better diagnostic modality for the detection of posterior segment pathology in traumatic and non-traumatic cataract patients. Two dimensional B-scan can be effective in routine examination of pre-operative cataract patients. Three-dimensional B-scan could be considered in cases where two-dimensional does not provide sufficient help in assessment of posterior segment pathology in cataract patients. Keywords: Cataract patients, Traumatic cataract patients, Non-traumatic cataract patients, B-scan

Evaluation of posterior segment ocular disorders using B-scan ultrasonography in patients attending a tertiary care teaching hospital Telangana India

Background: Ultrasonography is one of the most useful non-invasive techniques for evaluation of the Posterior segment of the eye. Objectives: to evaluate the posterior segment and identify any posterior segment disorders, using diagnostic B - scan ultrasonography in patients presenting with opaque ocular media. Methodology: Patients with opaque media were subjected for evaluation of the Posterior segment using a standard Ultrasound unit - MARVEL B-scan, consisting of diagnostic B scan and A scan biometry. Ultrasound probe was placed over the globe of the closed eye after applying coupling gel over the probe. The globe was scanned thoroughly using transverse, longitudinal, oblique and axial scans.Ultrasound image was analysed for any abnormalities both in real time and after freezing the image and findings were documented Results: Almost ¾ th of the patients with ocular trauma were found to have detectable posterior segment pathologies on b scan. Retinal detachment combined with vitreous hemorrhage was most common b scan finding in patients with ocular trauma.Posterior vitreous detachment was commonly observed pathology in 10 eyes followed by vitreous hemorrhage in 7 patients. Conclusion: B-scan ultrasonography is useful in the assessment of ocular traumatic and non – traumatic lesions and supplements clinical examination with valuable information.