Charge density wave in a SnSe2 layer on and the effect of surface hydrogenation.

We have carried out an investigation using density functional theory (DFT) of the atomic and electronic structures of SnSe2 layers on the surface and hydrogenation of this surface. We have considered a (2 × 2) SnSe2 superstructure oriented along the diagonal direction of the surface periodicity, for which scanning tunneling microscopy (STM) measurements have recently been reported. In the band structure calculations, while the s-p character surface state originating from each SnSe2 layer is determined, there is an additional half-filled surface state in the fundamental band gap region due to the Sn adatom. At the M̄ point in the Brillouin zone, a charge density wave (CDW) partial gap opening of ∼0.1 eV occurs between these surface states close to the Fermi level. Here, the CDW gap is caused by two reasons; (i) Fermi surface nesting, due to the inequivalent electron pockets at the M̄ point, and (ii) the out of plane weak electron-phonon coupling regime due to the mean-field (MF) theory (2Δ/kBTMF = 3.52). Upon hydrogen adsorption on the surface, we have obtained a ß-phase SnSe layer and SeH2 molecule with a bond angle of ∼90°. The hydrogenated surface pushes the surface state associated with the SnSe2 layer into the Si projected bulk band continuum. After SeH2 desorption, the work function drops from 5.20 eV to 4.39 eV.

Successful desensitization with chemotherapeutic drugs: a tertiary care center experience.

SUMMARY: Introduction.Hypersensitivity reactions to chemotherapeutic drugs are increasing all over the world, and desensitization to them has become the standard treatment approach. This study aimed to evaluate the characteristics of chemotherapeutic drug hypersensitivity reactions and the outcome of desensitization procedures. Methods. Between January 2017 and 2019, patients who have been desensitized to chemotherapeutic drugs were included retrospectively. Data were obtained from the medical records of the patients. Results. A total of 35 patients were evaluated; of whom 24 (68.5%) were female and 11 were male (31.5%). The mean age was 54.54 ± 13.39 (min-max: 41-69) years. Colorectal cancer was the most common malignancy (n:14, 40%). Desensitization was performed with oxaliplatin in 17 (48.5%), carboplatin in nine (25.7%), paclitaxel in four (11.4%), cisplatin in two (5.7%), irinotecan in two (5.7%), rituximab in two (5.7%), and docetaxel in one (2.8%) patients. Thirty four (97.1%) were successfully desensitized without any reactions. Anaphylaxis occurred during desensitization with rituximab and the procedure could not be completed. The reactions occurred during the first administration of the chemotherapeutic agent in five (14.2%) patients. Skin tests were performed on 26 (74.2%) patients. Skin prick and intradermal tests were positive in 7 (26.9%) and 12 (46.1%) patients, respectively. Conclusions. Desensitization is an effective and safe treatment approach for chemotherapeutic drug hypersensitivity and can be performed safely by observing general precautions to anaphylaxis.

Analysis of patients undergoing surgical treatment for primary spontaneous pneumothorax.

BACKGROUND: Primary spontaneous pneumothorax (psp) results from spontaneous rupture of bleb or bulla. Aims: We planned to discuss the etiologic factors, clinical and radiological findings, and treatment results of psp cases. MATERIALS AND METHODS: 402 patients were evaluated. Patients were divided into two groups as patients receiving positive results with thoracostomy and patients who received positive results"> thoracotomy/video-assisted thoracoscopic surgery (vats). Groups were compared. Results were evaluated"> using Chi-square or Fishers' exact test. P < 0.05 was considered as significant. RESULTS: Gender difference (P: 1.00) and localization of disease (P: 0.45)were not significant for psp. Smoking and being subtotal or total compared to partial had a substantial effect on the implementation of thoracotomy/vats (P < 0.05). Furthermore, psp was most frequently seen in August and September. DISCUSSION: Risk factors of psp are described as genetic predisposition, being tall, smoking, and autosomal dominant heredity. The main determinant factor in the treatment of psp is the degree of pneumothorax. CONCLUSION: Psp was frequently observed in smokers. The preferred method for overall psp is tube thoracostomy. Thoracotomy/vats is more commonly performed for subtotal or total psp compared to partial psp.

Electronic, phononic and superconducting properties of trigonal Li2 MSi2 (M = Ir, Rh).

We have used ab initio density functional theory to study electronic, mechanical, phononic, and superconducting properties of Li2 MSi2 (M = Ir, Rh), which has recently been produced as a new type of transition metal-based ternary compound in the trigonal structure (Horigane et al 2019 New J. Phys. 21 093056). The calculated electronic band structure and the density of states indicate that the Li2IrSi2 and Li2RhSi2 compounds are in metallic character. Mechanical properties such as elastic constants, bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and Debye temperature were calculated for these compounds. The calculated results suggest that the compounds are mechanically stable and behave in a ductile manner. The phonon spectra have no imaginary frequency, which proves that these compounds are dynamically stable. Electron-phonon coupling parameters confirm that they are weak-coupling superconductors. Although the influence of spin-orbit coupling in superconductivity is not significant for these compounds, it has a very small influence on electronic structure for Li2IrSi2. The calculated critical temperature ([Formula: see text]) values of 3.29 K for Li2IrSi2 and 2.82 K for Li2RhSi2 agree well with experimental estimates.

Transinguinal laparoscopic evaluation of contralateral side during unilateral inguinal hernia repair for children.

BACKGROUND: Inguinal hernia repair is a common procedure in daily pediatric surgical practice. OBJECTIVES: The present study was planned to find out whether transinguinal laparoscopic exploration (TILE) of the contralateral groin is effective in reducing the need of operation for contralateral metachronous inguinal hernia (CMIH) in children. STUDY DESIGN: Charts of 1103 children who underwent inguinal hernia repair between 2006 and 2016 were retrospectively analyzed. Eighty-eight children with bilateral hernia at the presentation were excluded, and 705 patients whose parents could be contacted by phone to get the latest information about children's condition were included in the study. RESULTS: Of the 705 children with unilateral inguinal hernia repair, 362 (51.4%) and 343 (48.6%) of them had right-sided and left-sided inguinal hernia, respectively. Transinguinal laparoscopic exploration was performed in 479 of the 705 children with unilateral hernia and a hernia or contralateral patent processus vaginalis (PPV) was found and ligated in %28.3 (n = 136) of them. Mean follow-up time was 60 ± 36 months. Fifteen (4.3%) of 479 patients who had TILE and 31 (13.6%) of 226 the patients who did not have TILE developed CMIH. When the videos of 15 patients who developed CMIH were reviewed, overlooked PPV was found in 10 (3.3%) patients who had TILE during early phases of institutional learning curve. DISCUSSION AND CONCLUSIONS: TILE of the contralateral side during pediatric inguinal hernia repair is a simple and effective method to evaluate contralateral PPV. This approach clearly and significantly reduces the need of operation for a metachronous hernia at a later date.

Role of interlekin-35 as a biomarker in patients with newly diagnosed Hashimoto's thyroiditis.

OBJECTIVE: Interleukin-35 (IL-35), an interleukin-12 (IL-12) cytokine family member, is shown to be a potent immunosuppressive and anti-inflammatory cytokine. Inducible regulatory T cells (Tregs) produce IL-35 that mediates the immune inhibitory function of Tregs. Growing evidence revealed that upregulation of IL-35 expression may play a critical role in the prevention of autoimmune diseases in various experimental autoimmunity models and vice versa. Hashimoto's thyroiditis (HT) is considered to be a Treg cell-related autoimmune disease with loss of self-tolerance. METHODS: One hundred-twenty eight subjects, newly diagnosed hypothyroid HT patients [56 overt (Group 1), 72 subclinical hypothyroid (Group 2)] and 38 healthy controls (Group 3) were enrolled in the study. The levels of serum IL-35 were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Serum IL-35 levels were lower in the HT group when compared with subclinical HT group [304.5 (834.6) pg/ml vs. 636.1 (1542.0) pg/ml, p=0.004] and control cases [304.5 (834.6) pg/ml vs. 1064.7 (2526.8) pg/ml, p<0.001]. Serum IL-35 levels were inversely associated with thyroid stimulating hormone (TSH; rs=-0.396, p<0.001) and anti-thyroid peroxidase antibodies (TPOAb; rs=-0.571, p<0.001) in whole group. Serum IL-35 were negatively associated with TSH (rs=-0.264, p=0.003) and TPOAb (rs=-0.735, p<0.001) in patients with Hashimoto's thyroiditis (Group 1 + Group 2). CONCLUSION: The results suggest that IL-35 may play a role in the pathogenesis of HT.

Endoscopic balloon dilatation of benign esophageal strictures in childhood: a 15-year experience.

The study aims to evaluate the effectiveness and safety of endoscopic balloon dilatation (EBD) in childhood benign esophageal strictures. The medical records of 38 patients who underwent EBD from 1999 to 2013 were retrospectively reviewed. Demographic features, diagnoses, features of strictures, frequency and number of EBD, complications, outcome, and recurrence data were recorded. Median age was 1.5 years (0-14), and female/male ratio was 17/21 (n = 38). Primary diagnoses were corrosive esophageal stricture (n = 19) and esophageal atresia (n = 19). The length of strictures were less than 5 cm in 78.9% (n = 30). No complication was seen in 86.8% (n = 33). Perforation was seen in 10.5% (n = 4), and recurrent fistula was seen in 2.7% (n = 1). Total treatment lasted for 1 year (1-11). Dysphagia was relieved in 60.5% (n = 23). Recurrence was seen in 31.6% (n = 12). Treatment effectiveness was higher, and complication rates were lower in strictures shorter than 5 cm compared with longer ones (70% vs. 25%, P < 0.05, and 3.4% vs. 37.5%, P < 0.05). Although there was no statistical difference, treatment effectiveness rates were lower and complication and recurrence rates were higher in corrosive strictures compared with anastomotic ones (P > 0.05). EBD is a safe and efficient treatment choice in esophageal strictures, especially in strictures shorter than 5 cm and anastomotic strictures.

Subclinical hypothyroidism in combination with vitamin D deficiency increases the risk of impaired left ventricular diastolic function.

OBJECTIVE: Subclinical hypothyroidism and vitamin D deficiency are common. The diastolic function of patients with both subclinical hypothyroidism and vitamin D deficiency remains unknown. This study aimed to investigate diastolic dysfunction in patients with both subclinical hypothyroidism and vitamin D deficiency. SUBJECTS AND METHODS: This study included 254 patients. All patients underwent standard Doppler echocardiography. Patients who had risk factors for diastolic dysfunction or had used L-thyroxine and vitamin D within the previous 3 months were excluded. Vitamin D deficiency was defined as a 25-OH-vitamin D level lower than 20 ng/ml, and vitamin D sufficiency was defined as a 25-OH-vitamin D level ≥ 30 ng/ml. Subclinical hypothyroidism was defined as a TSH level of 4.5-10 mU/l when the free T4 concentration was normal. RESULTS: The patients were divided into 4 groups. Group 1 (n=71) included patients with subclinical hypothyroidism and vitamin D deficiency; Group 2 (n=66) included patients with subclinical hypothyroidism and vitamin D sufficiency; Group 3 (n=65) included euthyroid patients with vitamin D deficiency; and Group 4 (n=52) included euthyroid patients with vitamin D sufficiency. LAVI (31.3 ± 3.2, 28.7 ± 3.0, 28.4 ± 3.4, and 27.9 ± 3.9; p<0.001) and E/E' values (11.2 ± 2.7, 8.9 ± 2.7, 9.1 ± 2.9, 8.8 ± 2.5; p<0.001) were significantly higher in Group 1 than in Groups 2, 3 and 4. E' values were significantly lower in Group 1 than in Groups 2, 3 and 4. CONCLUSION: The coexistence of subclinical hypothyroidism with vitamin D deficiency can lead to further deterioration in the LV diastolic function via the regulation of intracellular calcium and induction of inflammatory activity. Therefore, close follow-up of the diastolic functions of these patients could be beneficial.

The effect of penile urethral fat graft application on urethral angiogenesis.

BACKGROUND: Autologous fat grafts are rich in adipose-derived stem cells, providing optimal soft-tissue replacement and significant quantities of angiogenic growth factor. Although fat grafts (FG) are used in several clinical conditions, the use of FG in urethral repairs and the effects of FG to urethral repairs have not yet been reported. OBJECTIVE: An experimental study was performed to evaluate the effect of FG on urethral angiogenesis and tissue growth factor (GF) levels. STUDY DESIGN: Sixteen Wistar albino, adult, male rats were allocated into two groups: the control group (CG) (n = 8) and the experiment group (EG) (n = 8). After anesthetization of all rats, 3-mm vertical incisions were made on the urethras, and then sutured with interrupted 5/0 vicryl sutures. The operations were performed under a stereo dissecting microscope under magnification (×20). In the CG, no additional procedure was performed. In the EG after the same surgical procedure, 1 mm(3) FG was removed from the inguinal region by sharp dissection with a knife. The grafts were trimmed to 1 × 1 mm dimensions on millimeter paper. The FGs were placed on the repaired urethras. The skin was then closed. Samples from urethral and penile skin were taken 21 days after surgery in both groups. Density and intensity of staining with vascular-endothelial GF (VEGF), VEGF-receptor, and endothelial-GF receptor (EGFR) in the endothelial and mesenchymal cells of the penile urethral vessels were immunohistochemically evaluated. Data obtained from immunohistochemical evaluations were analyzed with SPSS 15.0. The P-values lower than 0.05 were considered as significant. RESULTS: Density of VEGF staining was significantly decreased in the vascular endothelium of the EG compared to the CG (P < 0.05). Density of the EGFR staining was significantly decreased in the vascular endothelium of the EG compared to the CG (P < 0.05) (Table). Intensity of VEGF, VEGF-R and EGFR staining was not significantly different between the two groups. There were no significant differences between groups regarding to VEGFR staining and mesenchymal examination. DISCUSSION: Decreased density was found in the VEGF staining in the vascular endothelium. This could be explained by the day that the tissues were harvested or because autologous fat grafts might cause decreased growth factor levels, which is contrary to the literature data. CONCLUSION: Fat grafting has an immunohistochemical effect on the growth factor levels that are related to angiogenesis after urethral repair. It is difficult to make a firm conclusion about the role of fat grafting on urethral healing. Therefore, future studies are needed to see if FG can be used as an alternative to other procedures in order to avoid complications.

Increased levels of galectin-3 were associated with prediabetes and diabetes: new risk factor?

PURPOSE: Galectin-3 (Gal-3) is a marker of cardiac fibrosis and predicts incident heart failure. Gal-3-deficient mice are resistant to multiple low-dose streptozotocin-induced diabetes. Recent experimental studies suggested an important role for Gal-3 in the regulation of adiposity, metaflammation and type 2 diabetes. This study aimed to examine the relationship between Gal-3 and newly diagnosed prediabetes and diabetes. METHODS: Gal-3 concentrations were measured in 118 participants and 56 age- and sex-matched healthy controls. All subjects underwent a 75-g oral glucose tolerance test and were stratified into normal, prediabetic, and diabetes mellitus subgroups. DM was defined as a plasma glucose level ≥126 mg/dL in the fasting state or ≥200 mg/dL in the second hour after glucose loading. Impaired fasting glucose was defined as an FPG level of 100-125 mg/dL, and impaired glucose tolerance was defined as a 2-h plasma glucose level of 140-199 mg/dL. RESULTS: Sixty-one patients had prediabetes (Group 1), 57 had diabetes (Group 2), and 56 had neither diabetes nor prediabetes (Group 3). Gal-3 levels correlated with FPG (r = 0.787, P < 0.01), 2hPG (r = 0.833, P < 0.01), CRP (r = 0.501, P < 0.01), and HOMA-IR (r = 0.518, P < 0.01). Gal-3 levels were higher in Group 2 than in Groups 1 and 3 [1,053.9 (358.1) and 744.1 (119.3) vs. 481.7 (175.4) pg/mL; P < 0.001]. Gal-3 is an independent predictor of diabetes in multivariate logistic analysis. In ROC analysis, a Gal-3 cutoff value of 803.55 pg/mL diagnoses diabetes with a sensitivity of 80.7 % and a specificity of 85.5 % (AUC = 0.912). CONCLUSIONS: Gal-3 is a promising biomarker for detecting prediabetes and diabetes.

Neutrophil-lymphocyte ratio may be superior to C-reactive protein for predicting the occurrence of postmenopausal osteoporosis.

OBJECTIVE: Recent studies revealed that inflammation plays a critical role in bone remodeling and the pathogenesis of postmenopausal osteoporosis, a major health concern. Neutrophil-lymphocyte ratio (NLR) is a cost-effective marker of inflammation that has been linked with several diseases. This study aimed to compare NLR and C-reactive protein (CRP) levels in osteopenic, osteoporotic, and control subjects and to assess the correlation between NLR levels, CRP, and bone mineral density (BMD) in postmenopausal women. METHODS: In this cross-sectional study, the relationship between NLR, CRP, and BMD in 438 women was investigated using uni- and multivariate analyses. BMD (g/cm²) was measured by dual-energy X-ray absorptiometry (DEXA) at the lumbar spine and femur. Complete blood count (CBC), CRP, glucose/lipid metabolism, and established risk factors were determined. RESULTS: In the osteoporotic group, NLR and CRP levels were found to be elevated as compared to the osteopenic and control groups (NLR: 4.68 ± 0.72, 3.17 ± 0.43, 2.01 ± 0.54; CRP: 12.3 ± 4.1, 4.1 ± 2.7, 3.2 ± 2.1, respectively). A negative correlation was present between NLR and the lumbar spine (L2-L4) and femoral neck BMD after adjusting other risk factors. There was no correlation between CRP levels and BMD after adjusting other risk factors. NLR was significantly associated with L2-L4 BMD (ß = -0.653, p<0.001) and femoral neck BMD (ß = -0.178, p<0.001), but CRP level had no association with BMD in a multivariate model. CONCLUSIONS: Our data indicate that NLR may be a better predictor than CRP for occurrence of osteoporosis in postmenopausal women.

Serum neutrophil gelatinase associated lipocalin and plasma nitric oxide levels in healthy and preeclamptic pregnants.

AIMS: The authors aimed to evaluate serum neutrophil gelatinase associated lipocalin (NGAL) and plasma nitric oxide (NO) levels in preeclamptic and healthy pregnant women above 24 gestation weeks. MATERIALS AND METHODS: Forty-nine healthy and 21 preeclamptic (total 70) pregnant women participated voluntarily in the study. Presence of 140 mmHg and above systolic and 90 mmHg and above diastolic blood pressure which emerges after 20th gestation week, proteinuria more than 300 mg/24 hour, and edema were used as diagnostic criterion for preeclamptic pregnant women. Measurements of serum NGAL and plasma NO were performed with enzyme linked immunosorbent assay (ELISA) and photometric method, respectively. RESULTS: Serum NGAL and plasma NO levels of healthy and preeclamptic groups did not show a statistical difference. In preeclamptic group, a statistically meaningful correlation was found between level of NGAL and body mass index (BMI) of sampling time, creatinine and NGAL, total protein and NO, and albumin and NO. CONCLUSIONS: Serum NGAL levels, correlated with serum creatinine levels in this study, may be the early marker of renal damage which may develop mainly due to inflammation and endothelial damage. The authors could not find a statistical difference for serum NGAL and plasma NO levels between healthy pregnant and preeclamptic groups. Varieties peculiar to humans in preeclampsia, impossibility of obtaining first trimester tissue material as an evidence of inadequate trophoblast invasion, and different appearance of maternal reaction to underlying main pathology in every case may restrict clarification of etiopathogenesis.

Rapid integrated rheo-optical and polarized Fourier-transform infrared spectrometry measurement system for polymer films undergoing chemo-mechanical changes.

The design and performance of a multisensory instrument to track physical and chemical changes of thin polymer films (typically 5 µm < thickness < 100 µm) subjected to thermal and mechanical treatments are described in this paper. For the first time, real-time measurements of spectral birefringence, true stress, true strain, and temperature are integrated together with ultra-rapid-scan polarized FT-IR spectrometer (URS-FT-IR) to investigate the relationships between true mechanical measures and structural features at different length scales. The rheo-optical properties (birefringence-true stress-true strain) are collected at a rate of 10 data points∕s and URS-FT-IR data are collected at a rate of 300 complete spectra∕s. The IR dichroism measurement is performed by exposing the sample to non-polarized IR beam in transmission mode with two mutually perpendicular polarizations, parallel and perpendicular to the stretching direction, received by detector unit. This design allows to analyze both polarizations simultaneously wavenumbers in the range of 500 cm(-1)-4000 cm(-1). Controlled processing parameters include air speed, air temperature, stretching rate, stretching ratio, stretch cycling, and holding times; while simultaneously measuring optical retardation, sample width, temperature, load cell, and both parallel and perpendicular IR spectra. Calibration and performance of this instrument is demonstrated with several film samples. These are: A polystyrene standard, an atactic polystyrene (homo-polymer), a polyurethane (consists of hard and soft segments) for physical changes during uniaxial deformation, and a polyamic acid during imidization reaction. This measurement system is particularly useful in unraveling molecular level details of complex physical and chemical events that take place during very fast deformation schemes (uniaxial stretching, retraction, relaxation, annealing, etc.) relevant to industrial processes. These include specific orientation behavior of each phase, block or filler, crystallization, relaxation and orientation state. It is also suited to track reaction rates and products in polymers undergoing thermal or photo curing.

Evaluation of contralateral kidney, liver and lung after extracorporeal shock wave lithotripsy in rabbits.

An experimental study was carried out to evaluate the effects of extracorporeal shock wave lithotripsy (ESWL) on contralateral kidney, liver and lung by histopathological and biochemical methods. Twelve New Zealand rabbits were allocated to two groups (n = 6). Tissues of control group (CG, n = 6) were harvested without any intervention. In ESWL group (EG), right kidneys were exposed to 3,000 shock waves at 14 kV energy using electro-hydraulic type ESWL device three times every other day. Both kidneys, liver, and right lobe of lung tissues in EG were harvested on seventh day. Kidneys were examined histopathologically for presence of glomerular and tubular injury, interstitial edema, congestion, inflammation and fibrosis. Livers were examined for hepatocyte vacuolization, congestion, portal inflammation and fibrosis. Lung tissues were examined for loss of normal structure, emphysema, interstitial congestion-edema, prominent alveolar septal vessels, interstitial inflammation, intra-alveolar hemorrhage, intraluminal hemorrhage, peribronchial edema, congestion, inflammation in bronchial wall and epithelial desquamation. Biochemical analysis of tissue samples was performed for oxidative injury markers. Histopathological evaluations revealed that tubular injury was found in both shocked and contralateral kidneys (p < 0.05). EG showed higher grades of portal fibrosis in liver and higher grades of peribronchial congestion in lung when compared to CG (p < 0.05). Biochemical evaluations of both kidneys showed that malondialdehyde levels were higher in EG than in CG (p < 0.05). ESWL causes histopathologic alterations both in shocked and contralateral kidneys. Extrarenal tissues such as liver and lung can be affected by shock waves histopathologically and oxidative injury of contralateral kidney may occur acutely after ESWL.

Real-time measurement system for tracking birefringence, weight, thickness, and surface temperature during drying of solution cast coatings and films.

This paper describes the design and performance of a new instrument to track temporal changes in physical parameters during the drying behavior of solutions, as well as curing of monomers. This real-time instrument follows in-plane and out-of-plane birefringence, weight, thickness, and surface temperature during the course of solidification of coatings and films through solvent evaporation and thermal or photocuring in a controlled atmosphere. It is specifically designed to simulate behavior of polymer solutions inside an industrial size, continuous roll-to-roll solution casting line and other coating operations where resins are subjected to ultraviolet (UV) curing from monomer precursors. Controlled processing parameters include air speed, temperature, initial cast thickness, and solute concentration, while measured parameters are thickness, weight, film temperature, in-plane and out-of-plane birefringence. In this paper, we illustrate the utility of this instrument with solution cast and dried poly (amide-imide)∕DMAc (Dimethylacetamide) solution, water based black paint, and organo-modified clay∕NMP (N-Methylpyrrolidone) solution. In addition, the physical changes that take place during UV photo polymerization of a monomer are tracked. This instrument is designed to be generic and it can be used for tracking any drying∕swelling∕solidification systems including paper, foodstuffs such as; grains, milk as well as pharmaceutical thin paste and slurries.

Colloid retention at the meniscus-wall contact line in an open microchannel.

Colloid retention mechanisms in partially saturated porous media are currently being researched with an array of visualization techniques. These visualization techniques have refined our understanding of colloid movement and retention at the pore scale beyond what can be obtained from breakthrough experiments. One of the remaining questions is what mechanisms are responsible for colloid immobilization at the triple point where air, water, and soil grain meet. The objective of this study was to investigate how colloids are transported to the air-water-solid (AWS) contact line in an open triangular microchannel, and then retained as a function of meniscus contact angle with the wall and solution ionic strength. Colloid flow path, meniscus shape and meniscus-wall contact angle, and colloid retention at the AWS contact line were visualized and quantified with a confocal microscope. Experimental results demonstrated that colloid retention at the AWS contact line was significant when the meniscus-wall contact angle was less than 16°, but was minimal for the meniscus-wall contact angles exceeding 20°. Tracking of individual colloids and computational hydrodynamic simulation both revealed that for small contact angles (e.g., 12.5°), counter flow and flow vortices formed near the AWS contact line, but not for large contact angles (e.g., 28°). This counter flow helped deliver the colloids to the wall surface just below the contact line. In accordance with DLVO and hydrodynamic torque calculations, colloid movement may be stopped when the colloid reached the secondary minimum at the wall near the contact line. However, contradictory to the prediction of the torque analysis, colloid retention at the AWS contact line decreased with increasing ionic strength for contact angles of 10-20°, indicating that the air-water interface was involved through both counter flow and capillary force. We hypothesized that capillary force pushed the colloid through the primary energy barrier to the primary minimum to become immobilized, when small fluctuations in water level stretched the meniscus over the colloid. For large meniscus-wall contact angles counter flow was not observed, resulting in less colloid retention, because a smaller number of colloids were transported to the contact line.