Use of commercial off-the-shelf digital cameras for scientific data acquisition and scene-specific color calibration

Author Posting. © Optical Society of America, 2014. This article is posted here by permission of Optical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Optical Society of America A: Optics, Image Science, and Vision 31 (2014): 312-321, doi:10.1364/JOSAA.31.000312.Commercial off-the-shelf digital cameras are inexpensive and easy-to-use instruments that can be used for quantitative scientific data acquisition if images are captured in raw format and processed so that they maintain a linear relationship with scene radiance. Here we describe the image-processing steps required for consistent data acquisition with color cameras. In addition, we present a method for scene-specific color calibration that increases the accuracy of color capture when a scene contains colors that are not well represented in the gamut of a standard color-calibration target. We demonstrate applications of the proposed methodology in the fields of biomedical engineering, artwork photography, perception science, marine biology, and underwater imaging.T. Treibitz is an Awardee of the Weizmann Institute of Science—National Postdoctoral Award Program for Advancing Women in Science and was supported by NSF grant ATM-0941760. D. Akkaynak, J. Allen, and R. Hanlon were supported by NSF grant 1129897 and ONR grants N0001406-1-0202 and N00014-10-1-0989 and U. Demirci by grants R01AI093282, R01AI081534, and NIH U54EB15408. J. Allen is grateful for support from a National Defense Science and Engineering Graduate Fellowship

Nanostructured Optical Photonic Crystal Biosensor for HIV Viral Load Measurement

Detecting and quantifying biomarkers and viruses in biological samples have broad applications in early disease diagnosis and treatment monitoring. We have demonstrated a label-free optical sensing mechanism using nanostructured photonic crystals (PC) to capture and quantify intact viruses (HIV-1) from biologically relevant samples. The nanostructured surface of the PC biosensor resonantly reflects a narrow wavelength band during illumination with a broadband light source. Surface-adsorbed biotarget induces a shift in the resonant Peak Wavelength Value (PWV) that is detectable with <10 pm wavelength resolution, enabling detection of both biomolecular layers and small number of viruses that sparsely populate the transducer surface. We have successfully captured and detected HIV-1 in serum and phosphate buffered saline (PBS) samples with viral loads ranging from 104 to 108 copies/mL. The surface density of immobilized biomolecular layers used in the sensor functionalization process, including 3-mercaptopropyltrimethoxysilane (3-MPS), N-gamma-Maleimidobutyryl-oxysuccinimide ester (GMBS), NeutrAvidin, anti-gp120, and bovine serum albumin (BSA) were also quantified by the PC biosensor

TIMP-2 gene transfer by positively charged PEG-lated monosized polycationic carrier to smooth muscle cells

Remodeling of the extracellular matrix resulting from increased secretion of metalloproteinase enzymes is implicated in restenosis following balloon angioplasty. Matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases play an essential role in both normal and pathological extracellular matrix degradation. Tissue inhibitor of matrix metalloproteinase- 2 is the most extensively studied tissue inhibitor of metalloproteinases inmyocardial tissue in animalmodels and clinical examples of cardiac disease; therefore it is selected for this study. Gene transfer of tissue inhibitor of matrix metalloproteinase-2 may have a therapeutic potential by inhibition of matrix metalloproteinase activity. We have used PEG-lated nanoparticles poly(St/PEG-EEM/DMAPM) which were synthesized previously in our laboratory. The nanoparticles, with an average size of 77.6 ± 2.05 nm with a zeta potential of +64. 4 ± 1.14 mVand 201.9 ± 1.83 nmwith +54.2 ± 0.77 mV were used in the transfection studies. Zeta Potential values and size of polyplex were appropriate for an effective transfection. TIMP-2 expression was detected by western blotting. Increased protein level in smoothmuscle cells according to non-transfected smooth muscle cells confirms the successful delivery and expression of the tissue inhibitor of matrix metalloproteinase- 2 gene with the non-viral vector transfection approach. © Springer Science+Business Media B.V. 2012

Ovarian reserve parameters and IVF outcomes in 510 women with poor ovarian response (POR) treated with intraovarian injection of autologous platelet rich plasma (PRP)

The aim of the current study was to characterize ovarian reserve parameters and IVF outcomes in women with a history of poor ovarian response (POR) treated with intraovarian injection of autologous platelet rich plasma (PRP). Reproductive age women (N=510; age range 30-45yo) diagnosed with POR based on Poseidon criteria were included in the study. PRP treatment resulted in higher AFC, higher serum AMH, lower serum FSH, and a higher number of mature oocytes and cleavage and blastocyst stage embryos. After PRP injection, 22 women (4.3%) conceived spontaneously, 14 (2.7%) were lost to follow up, and 474 (92.9%) attempted IVF. Among women who attempted IVF, 312 (65.8%) generated embryos and underwent embryo transfer, 83 (17.5%) achieved a pregnancy, and 54 (11.4%) achieved sustained implantation/live birth (SI/LB). In total, of the 510 women with POR and mean age of 40.3, PRP resulted in improvement of ovarian reserve parameters, a pregnancy rate of 20.5% and SI/LB rate of 12.9%. Our findings suggest that PRP treatment may be considered in women with POR. For wider clinical application, its clinical efficacy will need to be demonstrated in prospective randomized clinical trials

Statistical Modeling of Single Target Cell Encapsulation

High throughput drop-on-demand systems for separation and encapsulation of individual target cells from heterogeneous mixtures of multiple cell types is an emerging method in biotechnology that has broad applications in tissue engineering and regenerative medicine, genomics, and cryobiology. However, cell encapsulation in droplets is a random process that is hard to control. Statistical models can provide an understanding of the underlying processes and estimation of the relevant parameters, and enable reliable and repeatable control over the encapsulation of cells in droplets during the isolation process with high confidence level. We have modeled and experimentally verified a microdroplet-based cell encapsulation process for various combinations of cell loading and target cell concentrations. Here, we explain theoretically and validate experimentally a model to isolate and pattern single target cells from heterogeneous mixtures without using complex peripheral systems.Wallace H. Coulter Foundation (Young Investigator in Bioengineering Award)National Institutes of Health (U.S.) (Grant R01AI081534)National Institutes of Health (U.S.) (Grant R21AI087107

Living Bacterial Sacrificial Porogens to Engineer Decellularized Porous Scaffolds

Decellularization and cellularization of organs have emerged as disruptive methods in tissue engineering and regenerative medicine. Porous hydrogel scaffolds have widespread applications in tissue engineering, regenerative medicine and drug discovery as viable tissue mimics. However, the existing hydrogel fabrication techniques suffer from limited control over pore interconnectivity, density and size, which leads to inefficient nutrient and oxygen transport to cells embedded in the scaffolds. Here, we demonstrated an innovative approach to develop a new platform for tissue engineered constructs using live bacteria as sacrificial porogens. E.coli were patterned and cultured in an interconnected three-dimensional (3D) hydrogel network. The growing bacteria created interconnected micropores and microchannels. Then, the scafold was decellularized, and bacteria were eliminated from the scaffold through lysing and washing steps. This 3D porous network method combined with bioprinting has the potential to be broadly applicable and compatible with tissue specific applications allowing seeding of stem cells and other cell types

Chuanxiongzine relaxes isolated corpus cavernosum strips and raises intracavernous pressure in rabbits

It has been shown that there are many Chinese traditional herbals that can enhance sexual activity. Chuanxiongzine is a vasoactive ingredient that has been isolated and purified from Ligusticum chuanxiong Hort. In previous studies, it has been found that chuanxiongzine was effective in relaxing rabbit corpus cavernosum smooth muscle. We determined the effects of chuanxiongzine on relaxation of isolated corpus cavernosum strips in vitro and on increase of intracavernous pressure (ICP) in vivo in rabbits. Chuanxiongzine caused a concentration-dependent relaxation of phenylephrine precontracted isolated corpus cavernosum strips (EC50 1.58 × 10−4 mol l−1), which were endothelium independent and NO independent. However, the guanylyl cyclase inhibitor 1-H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one significantly shifted the chuanxiongzine concentration–response relationship to the right. Although there was no significant difference in the level of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) in isolated corpus cavernosum strips treated with chuanxiongzine or vehicle, chuanxiongzine caused a significant rise in the level of cGMP and cAMP in isolated corpus cavernosum strips pretreated with the activator of adenylyl cyclase forskolin and the source of NO sodium nitroprusside. In an in vivo study, chuanxiongzine dose-dependently raised ICP after the intracavernous injection of its cumulative doses (0.5, 1, 2 and 5 mg kg−1). The ICP increased from baseline to 19.1±3.7, 24.8±2.1, 30.2±4.8 and 39.7±6.1 mm Hg, respectively, and the duration of tumescence ranged from 8.5±2.8 to 22.9±7.3 min. Our results show that chuanxiongzine can relax isolated corpus cavernosum strips of rabbits in vitro and increase ICP of rabbits in vivo, which is neither endothelium dependent nor NO dependent, but may be partly mediated by the inhibition of cAMP phosphodiesterase or cGMP phosphodiesterase

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P &lt; 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P &lt; 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks