Considerations in the Surgical Management of Unicuspid Aortic Stenosis.

Unicuspid aortic valve (UAV) stenosis is a rare condition accounting for 5% of non-rheumatic aortic stenosis. The diagnosis can be difficult to make prior to surgical intervention and transesophageal echocardiography has been demonstrated to be more accurate in making the diagnosis compared to transthoracic echocardiography. The presence of a posteriorly located aortic orifice on the short-axis views, with one or two visible raphe anteriorly; the absence of commissures (acommissural); or the presence of a lone commissure (unicommissural) between the left and noncoronary, or the left and right cusps suggests the diagnosis. Patients with UAV are predominantly males and present with stenosis about a decade earlier than those with the more prevalent bicuspid aortic valves (BAV). They more commonly present with aortic annular dilatation and have fewer comorbidities at presentation compared to patients with BAV. Surgical management of UAV stenosis includes aortic valve replacement through standard open heart surgery or percutaneous transcatheter aortic valve replacement (TAVR), aortic valve repair either by bicuspidization, tricuspidization or trileaflet reconstruction, or the Ross procedure. Patients with UAV stenosis require less concomitant coronary or other cardiac procedures when they need surgical intervention, but are about a decade younger at the time of their death. UAV stenosis is a distinct congenital anomaly with a different natural course than BAV. Surgical management should be individualized based on the patient's age at presentation, aortoannular anatomy, and associated cardiac conditions.

Surgical Correction of Aberrant Right Coronary Anomalies Stranding an Aortic Commissure with and Without Unroofing.

The technique for successful surgical correction of an anomalous origin of the right coronary artery from the opposite aortic cusp with an aberrant course between the aorta and pulmonary artery is illustrated in a symptomatic 62-year-old woman. The intramural course of the right coronary artery traversed the tip of the commissure between the anterior and posterior leaflets, and its repair entailed unroofing of the intramural segment from inside the aortic intima. This technique required resuspension of the overlying commissure to maintain optimal aortic valve leaflet coaptation and prevent aortic insufficiency. Modifications of this technique have been utilized by us whenever the intramural segment traversed behind the commissure. In these cases, partial or subtotal unroofing of the intramural segment was performed to preserve the integrity of the intima behind the overlying commissure. More recently, we have performed the surgical correction by probing the intramural segment within the aortic wall to its most anterior location and then performing a wide anterior unroofing in the aortic intima, and marsupializing the aortic and coronary intima to avoid dissection or intimal flap development. We favor utilizing these techniques of anatomic correction of the anomalous coronary to other techniques involving coronary artery bypass grafting of the anomalous coronary, especially in adult patients, as unroofing provides more lasting results.

Diagnosis and management of primary effusion lymphoma in the immunocompetent and immunocompromised hosts.

Primary effusion lymphoma (PEL) is an uncommon non-Hodgkin lymphoma associated with human herpes virus-8 (HHV-8) that grows mainly in serous body cavities. The most common presentation of PEL is that of a young immunocompromised male with shortness of breath, as the pleural cavity is most commonly affected. Diagnosis is primarily based on fluid cytology in which PEL cells display variable morphology and a null lymphocyte immunophenotype; however, evidence of HHV-8 infection within the neoplastic cell is essential. Patients have commonly been treated with systemic multidrug chemotherapy and antiretroviral therapy if they were HIV positive or were immunocompromised for other reasons. In the immunocompetent patient, there have been no agreed-upon pathways for management of this condition. Progression of disease is common and median survival is approximately 6 months. Novel intrapleural treatments with antiviral agents such as intracavity cidofovir have shown to be effective in controlling local disease, and ongoing clinical trials may provide some promise in the treatment for this condition.

A Novel Design of Complementary Split Ring Resonator Metamaterial-Based Low-Profile MIMO Antenna with Defected Ground Structure for S/C/X/Ka Band Applications.

The article represents the design of two port-based printed MIMO antenna structures that have the advantages of low profile, simple structure, good isolation, peak gain, directive gain, and reflection coefficient. The performance characteristics are observed for the four design structures by cropping the patch region, loading the slits near the hexagonal-shaped patch, and adding and removing the slots in the ground area. The antenna provides a least reflection coefficient of -39.44 dB, a maximum electric field of patch region of 33.3 V/cm, a total gain of 5.23 dB, and good values of total active reflection coefficient and diversity gain. The proposed design provides nine bands' response, a peak bandwidth of 2.54 GHz, and a peak bandwidth of 26.127 dB. The four proposed structures are fabricated using a low-profile material to support mass production. The comparison among simulated and fabricated structures is included to check the authenticity of the work. The performance assessment of the proposed design with other published articles is carried out for the performance observation. The suggested technique is analyzed over the wideband of frequency region 1 GHz to 14 GHz. The multiple band responses make the proposed work suitable for wireless applications in S/C/X/Ka bands.

Design and Fabrication of a Low-Cost, Multiband and High Gain Square Tooth-Enabled Metamaterial Superstrate Microstrip Patch Antenna.

The manuscript represents a novel square tooth-enabled superstrate metamaterial loaded microstrip patch antenna for the multiple frequency band operation. The proposed tooth-based metamaterial antenna provides better gain and directivity. Four antenna structures are numerically investigated for the different geometry of the patch and tooth. These proposed structures are simulated, fabricated, measured, and compared for the frequency range of 3 GHz to 9 GHz. The electrical equivalent model of the split-ring resonator is also analyzed in the manuscript. The comparative analysis of all of the proposed structures has been carried out, in terms of several bands, reflectance response, VSWR, gain and bandwidth. The results are compared with previously published works. The effects are simulated using a high-frequency structure simulator tool with the finite element method. The measured and fabricated results are compared for verification purposes. The proposed structure provides seven bands of operation and 8.57 dB of gain. It is observed that the proposed design offers the multiple frequency band operation with a good gain. The proposed tooth-based metamaterial antenna suits applications, such as the surveillance radar, satellite communication, weather monitoring and many other wireless devices.

A surface plasmon resonance nanostructure containing graphene and BaTiO3 layers for sensitive defection of organic compounds.

Organic compound-based sensors are used in a variety of significant fields, including medical research, azeotropic calibration, vegetable oil extraction, the shoe industry and geothermal power plants. Here, a high-performance, two-dimensional material-based organic compound sensor has been proposed using a surface plasmon resonance (SPR) nanostructure consisting of a BK7 glass prism, Ag, BaTiO3, Ag, graphene and sensing layer. The reflectivity curves of the SPR device have been investigated when the sensing media are Pentane, n-Hexane, n-Heptane and n-Octane. The thickness of the BaTiO3 layer and the number of graphene sheets have been optimized to maximize the sensitivity. The highest sensitivity attained is 220.83 deg/RIU for n-Octane with 45 nm silver/10 nm BaTiO3/8 nm silver and four layers of graphene. We believe that the SPR-based sensors are simple and can replace the spectrometry, chromatography and electrochemical based sensors. The proposed design is extremely effective for diverse applications in biological, industrial and chemical detection because of its simple structure and great performance.

Detection of Virus SARS-CoV-2 Using a Surface Plasmon Resonance Device Based on BiFeO3-Graphene Layers.

Coronavirus disease (COVID-19) pandemic outbreak is being investigated by severe respirational syndrome coronavirus-2 (SARS-CoV-2) as a global health issue. It is crucial to propose sensitive and rapid coronavirus detectors. Herein, we propose a biosensor based on surface plasmon resonance (SPRE) for the detection of SARS-CoV-2 virus. To achieve improved sensitivity, a BiFeO3 layer is inserted between a metal (Ag) thin film and a graphene layer in the proposed SPRE device so that it has the structure BK7 prism/ Ag/ BiFeO3/ graphene/ analyte. It has been demonstrated that a small variation in the refractive index of the analyte can cause a considerable shift in the resonance angle caused by the remarkable dielectric properties of the BiFeO3 layer, which include a high index of refraction and low loss. The proposed device has shown an extremely high sensitivity of 293 deg/RIU by optimizing the thicknesses of Ag, BiFeO3, and the number of graphene sheets. The proposed SPRE-based sensor is encouraging for use in various sectors of biosensing because of its high sensitivity.

Design and Fabrication of Compact, Multiband, High Gain, High Isolation, Metamaterial-Based MIMO Antennas for Wireless Communication Systems.

We proposed a novel approach based on a complementary split-ring resonator metamaterial in a two-port MIMO antenna, giving high gain, multiband results with miniature size. We have also analyzed a circular disk metasurface design. The designs are also defected using ground structure by reducing the width of the ground plane to 8 mm and etching all other parts of the ground plane. The electric length of the proposed design is 0.5λ × 0.35λ × 0.02λ. The design results are also investigated for a different variation of complementary split-ring resonator ring sizes. The inner and outer ring diameters are varied to find the optimized solution for enhanced output performance parameters. Good isolation is also achieved for both bands. The gain and directivity results are also presented. The results are compared for isolation, gain, structure size, and the number of ports. The compact, multiband, high gain and high isolation design can apply to WiMAX, WLAN, and satellite communication applications.

Multivariable advanced nonlinear controller for bioethanol production in a non-isothermal fermentation bioreactor.

Design for fermentation bioreactor controllers is challenged by the nonlinear process kinetics and the lack of online measurements for key variables. This work developed a multi-input, multi-output advanced nonlinear control structure for a continuous, non-isothermal, constant volume fermentation bioreactor. Utilizing feedback linearization control for the bioreactor feed to regulate glucose concentration, and backstepping control for the cooling jacket feed to regulate reactor temperature. A developed novel estimator for biomass concentration was incorporated to provide online estimates for the unmeasurable state variable. Simulation results showed the control structure ability in efficiently establishing a combination of dynamic and fixed set points, despite disturbances in the bioreactor feed temperature and glucose concentration. Expanded bioreactor control authority increased operational flexibility and enhanced the potential for performance improvements. This work illustrated the effectiveness of feedback linearization and backstepping control in designing controllers for biological systems with nonlinear dynamics, complex interactions, and input disturbances.

Surface plasmon resonance biosensor based on graphene layer for the detection of waterborne bacteria.

As a result of the risks that waterborne bacteria bring to the human body, identifying them in drinking water has become a global concern. In this article, a highly sensitive surface plasmon resonance (SPR) biosensor consisting of prism, Ag, graphene, affinity layer and sensing medium is proposed for rapid detection of the waterborne bacteria. Four SPR-based sensors are first studied with the structures prism/Ag/sensing medium, prism/Ag/affinity layer/sensing medium, prism/Ag/graphene/sensing medium, and prism/Ag/graphene/affinity layer/sensing medium. The latter structure is found to have the highest sensitivity so it is considered for further investigations. Four different commonly used prisms are then demonstrated which are N-FK51A, 2S2G, SF10 and BK7. The structure with the prism N-FK51A is found to correspond to the highest sensitivity so it is considered for further investigations. The structure parameters are then optimized. The proposed SPR sensor can achieve high sensitivity of about 221.63 °/RIU for Escherichia coli and 178.12 °/RIU for Vibrio cholera bacteria with an average value of 199.87 °/RIU. We believe that the proposed structure will open a new window in the field of microorganism detections.

Optical Detection of Fat Concentration in Milk Using MXene-Based Surface Plasmon Resonance Structure.

MXene (Ti3C2Tx) has emerged very recently as an interacting material for surface plasmon resonance (SPR) configuration. It was discovered that Ti3C2Tx can facilitate the adsorption of biomolecules due to its higher binding energies, stronger interaction between matter and light, and larger surface area. In this work, a two-dimensional Ti3C2Tx and silicon layer-based SPR refractometric sensor is proposed for the sensitive and fast detection of milk fat concentration due to the high significance of this issue to people all over the world. The proposed SPR structure employs BK7 (BK7 is a designation for the most common Borosilicate Crown glass used for a variety of applications in the visible range) as a coupling prism and silver as a metal layer. The layer thicknesses and the number of Ti3C2Tx sheets are optimized for the highest performance. The highest reached sensitivity is 350 deg./RIU with 50 nm silver and 4 nm silicon with a monolayer of Ti3C2Tx, which is ultra-high sensitivity compared to the latest work that utilizes SPR configuration. The proposed SPR-based sensor's ultra-high sensitivity makes it more attractive for usage in a variety of biosensing applications.

Non-small cell lung carcinoma spheroid models in agarose microwells for drug response studies.

There is a growing interest in developing personalized treatment strategies for each cancer patient, especially those with non-small cell lung carcinoma (NSCLC) which annually accounts for the majority of cancer related deaths in the US. Yet identifying the optimal NSCLC treatment strategy for each cancer patient is critical due to a multitude of mutations, some of which develop following initial therapy and can result in drug resistance. A key difficulty in developing personalized therapies in NSCLC is the lack of clinically relevant assay systems that are suitable to evaluate drug sensitivity using a minuscule amount of patient-derived material available following biopsies. Herein we leverage 3D printing to demonstrate a platform based on miniature microwells in agarose to culture cancer cell spheroids. The agarose wells were shaped by 3D printing molds with 1000 microwells with a U-shaped bottom. Three NSCLC cell lines (HCC4006, H1975 and A549) were used to demonstrate size uniformity, spheroid viability, biomarker expressions and drug response in 3D agarose microwells. Results show that our approach yielded spheroids of uniform size (coefficient of variation <22%) and high viability (>83% after 1 week-culture). Studies using epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKIs) drugs gefitinib and osimertinib showed clinically relevant responses. Based on the physical features, cell phenotypes, and responses to therapy of our spheroid models, we conclude that our platform is suitable for in vitro culture and drug evaluation, especially in cases when tumor sample is limited.

Current outcomes of simultaneous carotid endarterectomy and coronary artery bypass graft surgery in North America.

OBJECTIVE: Management of patients with concomitant carotid and coronary artery disease has been controversial. Divergent strategies have been employed, including simultaneous carotid endarterectomy and coronary bypass (SCC) versus various staged procedures. Although no strict comparison group is available, this study defines current outcomes of SCC, compared qualitatively to two reference categories. METHODS: Utilizing the STS database from 2003 to 2007, patients who had SCC were compared with patients with cerebrovascular disease who had coronary bypass (CABG) with prior carotid endarterectomy (CEA), and those with carotid Doppler stenosis >75% and no carotid intervention. Logistic regression analysis adjusted for differences in baseline characteristics and operative mortality (OM), and a composite of neurological complications (NC) was assessed. RESULTS: Of 745,769 patients who underwent isolated CABG with/without CEA, 108,212 (14%) had cerebrovascular disease. Of this group, 5,732 (5%) underwent SCC. The SCC group had more males and lower preoperative risk factors. After statistical adjustment for all baseline differences, SCC had clinically and statistically higher OM and NC compared with any of the reference groups, with 20-40% higher event risk. CONCLUSIONS: Although no quantitative control group exists for comparison, SCC as recently performed in North America has a high risk compared with any of the reference groups. Suboptimal results associated with the SCC strategy suggest a need for quality improvement and research on the optimal management of patients with simultaneous carotid and coronary disease.

Detection of Promoter DNA Methylation in Urine and Plasma Aids the Detection of Non-Small Cell Lung Cancer.

PURPOSE: Low-dose CT screening can reduce lung cancer-related mortality. However, CT screening has an FDR of nearly 96%. We sought to assess whether urine samples can be a source for DNA methylation-based detection of non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: This nested case-control study of subjects with suspicious nodules on CT imaging obtained plasma and urine samples preoperatively. Cases (n = 74) had pathologic confirmation of NSCLC. Controls (n = 27) had a noncancer diagnosis. We detected promoter methylation in plasma and urine samples using methylation on beads and quantitative methylation-specific real-time PCR for cancer-specific genes (CDO1, TAC1, HOXA7, HOXA9, SOX17, and ZFP42). RESULTS: DNA methylation at cancer-specific loci was detected in both plasma and urine, and was more frequent in patients with cancer compared with controls for all six genes in plasma and in CDO1, TAC1, HOXA9, and SOX17 in urine. Univariate and multivariate logistic regression analysis showed that methylation detection in each one of six genes in plasma and CDO1, TAC1, HOXA9, and SOX17 in urine were significantly associated with the diagnosis of NSCLC, independent of age, race, and smoking pack-years. When methylation was detected for three or more genes in both plasma and urine, the sensitivity and specificity for lung cancer diagnosis were 73% and 92%, respectively. CONCLUSIONS: DNA methylation-based biomarkers in plasma and urine could be useful as an adjunct to CT screening to guide decision-making regarding further invasive procedures in patients with pulmonary nodules.

Endovascular treatment of aortic aneurysms: techniques and clinical update.

Open repair of abdominal and thoracic aortic aneurysms continues to be associated with considerable morbidity and mortality. Endovascular repair of abdominal and thoracic aortic aneurysms has evolved over the past few years and has significantly reduced the morbidity of aortic aneurysm repair compared with the standard open surgical procedures. Several devices have been approved for clinical use for this purpose. This has allowed the treatment of patients who are otherwise at high risk for open repair. This review paper aims to (1) describe the general principles of use for endovascular devices and review the radiographic features and clinical trials for the devices in current use, (2) present the results of the clinical trials that led to the approval and marketing of the current devices, and (3) review new techniques and approaches for the treatment of aortic aneurysms.

Left Atrial and Carotid Body Paraganglioma.

We report a rare case of left atrial paraganglioma with a synchronous carotid body paraganglioma in a 30-year-old man with succinate dehydrogenase B gene mutation. The patient initially presented with a neck mass and palpitations. Laboratory test results showed elevated catecholamine levels. A cardiac paraganglioma was identified by computed tomography, meta-iodobenzylguanidine scintigraphy, and magnetic resonance imaging. Surgical resection of both paragangliomas were performed on two separate occasions. Serum and urine catecholamine levels returned to normal range. On follow-up, there was no recurrence of the cardiac paraganglioma. Radiotherapy was subsequently initiated for recurrence in the carotid body paraganglioma.