Factors Related to Proximal Junctional Kyphosis and Device Failure in Patients with Early-Onset Scoliosis Treated with a Traditional Dual Growing Rod: A Single Institution Study.

STUDY DESIGN: Observational study. PURPOSE: Investigation of factors related to proximal junctional kyphosis (PJK) and device failure in patients with early-onset scoliosis. OVERVIEW OF LITERATURE: The use of growth-friendly devices, such as traditional dual growing rod (TDGR) for the treatment of earlyonset scoliosis (EOS), may be associated with important complications, including PJK and device failure. METHODS: Thirty-five patients with EOS and treated with TDGR from 2014 to 2021 with a minimum follow-up of 2 years were retrospectively evaluated. Potential risk factors, including demographic factors, disease etiology, radiological measurements, and surgical characteristics, were assessed. RESULTS: PJK was observed in 19 patients (54.3%), and seven patients (20%) had device failure. PJK was significantly associated with global final kyphosis change (p=0.012). No significant correlation was found between the rod angle contour, type of implant, connector design, and the risk of PJK or device failure. CONCLUSIONS: Treatment of EOS with TDGR is associated with high rates of complications, particularly PJK and device failure. The device type may not correlate with the risk of PJK and device failure. The progression of thoracic kyphosis during multiple distractions is an important risk factor for PJK.

EOS® is reliable to evaluate spinopelvic parameters: a validation study.

BACKGROUND: Sagittal and coronal standing radiographs have been the standard imaging for assessing spinal alignment. However, their disadvantages include distortion at the image edges and low interobserver reliability in some parameters. EOS® is a low-dose biplanar digital radiographic imaging system that can avoid distortion by obtaining high-definition images. METHODS: This study aimed to evaluate spinopelvic parameters in conventional lateral C1S1 upright radiographs and EOS® images and compare them. Patients with non-deformity changes were subjected to routine clinical examinations. Plain AP and lateral X-ray radiographs were obtained along the entire spine length. Patients were also referred for full-length EOS® of the spine. Thoracic Kyphosis (TK), Lumbar Lordosis (LL), Pelvic Tilt (PT), Sacral Slope (SS), Pelvic Incidence (PI), and Sagittal Vertical Axis (SVA) were measured in the two studies by an orthopedic surgeon and a radiologist using PACS software. Also, the orthopedic surgeon evaluated the studies again after two weeks. Intra- and inter-observer reliability was then assessed using the interclass correlation coefficient (ICC). Also, the coefficient of variation was used to assess intra- and inter-observer reliability. Bland-Altman plots were drawn for each parameter. RESULTS: The mean age was 48.2 ± 6.6 years. Among the 50 patients, 30 (60%) were female. The mean ICC for TK, LL, PT, SS, PI, and SVA in EOS® images are 0.95, 0.95, 0.92, 0.90, 0.94, and 0.98, respectively, and in C1S1 radiography images, it was 0.92, 0.87, 0.94, 0.88, 0.93, and 0.98, respectively which shows good to excellent results. The coefficient of variation for intraobserver reliability was relatively low (< 18.6%), while it showed higher percentages in evaluating interobserver reliability (< 54.5%). Also, the Bland-Altman plot showed good agreement for each parameter. CONCLUSION: Spinopelvic parameters, e.g., TK, LL, SS, PI, and SS, in EOS® are reliable and comparable to those in conventional lateral upright C1S1 radiographs.

Perioperative complications of symptomatic congenital kyphosis: a retrospective cohort study.

BACKGROUND: Despite the recent improvements in the surgical treatment of congenital kyphosis, this surgery may be associated with high rate of complications "particularly when patients are symptomatic preoperatively". MATERIALS AND METHODS: Medical profiles of 40 patients with symptomatic congenital kyphosis were retrospectively reviewed. Perioperative complications were recorded and divided in two groups including catastrophic complications (neurologic deficit, pulmonary thromboembolic events, and death) and major complications (infection, deep vein thrombosis, device failure, and dural injury). RESULTS: Catastrophic surgical complications occurred in nine (22.5%) patients including seven neurological deficits and two death. A significant association was observed between the incidence of major complications and type III of congenital kyphosis (P = 0.021). Major complications occurred in 14 (30%) patients. CONCLUSION: Surgical treatment significantly improve symptomatic congenital kyphosis deformity; however, surgery of symptomatic patient may be associated with higher rate of complications and even death.

Highly sensitive label-free biosensor: graphene/CaF2 multilayer for gas, cancer, virus, and diabetes detection with enhanced quality factor and figure of merit.

One of the primary goals for the researchers is to create a high-quality sensor with a simple structure because of the urgent requirement to identify biomolecules at low concentrations to diagnose diseases and detect hazardous chemicals for health early on. Recently graphene has attracted much interest in the field of improved biosensors. Meanwhile, graphene with new materials such as CaF2 has been widely used to improve the applications of graphene-based sensors. Using the fantastic features of the graphene/CaF2 multilayer, this article proposes an improvement sensor in the sensitivity (S), the figure of merit (FOM), and the quality factor (Q). The proposed sensor is based on the five-layers graphene/dielectric grating integrated with a Fabry-Perot cavity. By tuning graphene chemical potential (µc), due to the semi-metal features of graphene, the surface plasmon resonance (SPR) waves excited at the graphene/dielectric boundaries. Due to the vertical polarization of the source to the gratings and the symmetry of the electric field, both corners of the grating act as electric dipoles, and this causes the propagation of plasmonic waves on the graphene surface to propagate towards each other. Finally, it causes Fabry-Perot (FP) interference on the surface of graphene in the proposed structure's active medium (the area where the sample is located). In this article, using the inherent nature of FP interference and its S to the environment's refractive index (RI), by changing a minimal amount in the RI of the sample, the resonance wavelength (interferometer order) shifts sharply. The proposed design can detect and sense some cancers, such as Adrenal Gland Cancer, Blood Cancer, Breast Cancer I, Breast Cancer II, Cervical Cancer, and skin cancer precisely. By optimizing the structure, we can achieve an S as high as 9000 nm/RIU and a FOM of about 52.14 for the first resonance order (M1). Likewise, the remarkable S of 38,000 nm/RIU and the FOM of 81 have been obtained for the second mode (M2). In addition, the proposed label-free SPR sensor can detect changes in the concentration of various materials, including gases and biomolecules, hemoglobin, breast cancer, diabetes, leukemia, and most alloys, with an accuracy of 0.001. The proposed sensor can sense urine concentration with a maximum S of 8500 nm/RIU and cancers with high S in the 6000 nm/RIU range to 7000 nm/RIU. Also, four viruses, such as M13 bacteriophage, HIV type one, Herpes simplex type 1, and influenza, have been investigated, showing Maximum S (for second resonance mode of λR(M2) of 8000 nm/RIU (λR(M2) = 11.2 µm), 12,000 nm/RIU (λR(M2) = 10.73 µm), 38,000 nm/RIU (λR(M2) = 11.78 µm), and 12,000 nm/RIU (λR(M2) = 10.6 µm), respectively, and the obtained S for first resonance mode (λR(M1)) for mentioned viruses are 4740 nm/RIU (λR(M1) = 8.7 µm), 8010 nm/RIU (λR(M1) = 8.44 µm), 8100 nm/RIU (λR(M1) = 10.15 µm), and 9000 (λR(M1) = 8.36 µm), respectively.

Graphene-based optofluidic tweezers for refractive-index and size-based nanoparticle sorting, manipulation, and detection.

This work proposes a novel design composed of graphene nanoribbons-based optofluidic tweezers to manipulate and sort bio-particles with radii below 2.5 nm. The suggested structure has been numerically investigated by the finite difference time domain (FDTD) method employing Maxwell's stress tensor analysis (MST). The finite element method (FEM) has been used to obtain the electrostatic response of the proposed structure. The tweezer main path is a primary channel in the center of the structure, where the microfluidic flow translates the nanoparticle toward this channel. Concerning the microfluid's drag force, the nanoparticles tend to move along the length of the main channel. The graphene nanoribbons are fixed near the main channel at different distances to exert optical forces on the moving nanoparticles in the perpendicular direction. In this regard, sub-channels embedding in the hBN layer on the Si substrate deviate bio-particles from the main path for particular nanoparticle sizes and indices. Intense hotspots with electric field enhancements up to 900 times larger than the incident light are realized inside and around the graphene ribbons. Adjusting the gap distance between the graphene nanoribbon and the main channel allows us to separate the individual particle with a specific size from others, thus guiding that in the desired sub-channel. Furthermore, we demonstrated that in a structure with a large gap between channels, particles experience weak field intensity, leading to a low optical force that is insufficient to detect, trap, and manipulate nanoparticles. By varying the chemical potential of graphene associated with the electric field intensity variations in the graphene ribbons, we realized tunability in sorting nanoparticles while structural parameters remained constant. In fact, by adjusting the graphene Fermi level via the applied gate voltage, nanoparticles with any desired radius will be quickly sorted. Moreover, we exhibited that the proposed structure could sort nanoparticles based on their refractive indices. Therefore, the given optofluidic tweezer can easily detect bio-particles, such as cancer cells and viruses of tiny size.

Multifunctional graphene-based optoelectronic structure based on a Fabry-Perot cavity enhanced by a metallic nanoantenna.

Optical communications systems are continuously miniaturized to integrate several previously separate optoelectronic devices, organized with silicon-based incorporated circuits, onto a distinct substrate. Modulators and photodetectors have essential roles in photonic systems and operate with different mechanisms. Integrating them into one device is complex and challenging, but these multifunctional devices have numerous advantages. This article uses a graphene/hBN-based structure to modulate, detect, and absorb any signal with the desired frequency in the THz range. The proposed system comprises one unpatterned graphene sheet embedded in bulk hBN with the periodic gold/palladium nanostructure beneath and below it. The perfect absorption, a modulation depth of 100%, and photodetection of more than 20 A/W at any desired frequency can be verified.

High bandwidth and responsivity mid-infrared graphene photodetector based on a modified metal-dielectric-graphene architecture.

In this paper, a novel graphene-based mid-infrared photoconductive photodetector is designed that is composed of nanophotodetectors in series and parallel forming an array. The whole structure utilizes a single "unpatterned" graphene layer in a modified metal-dielectric-graphene (MDG) architecture that is composed of a conventional MDG structure combined with additional nanoelectrodes for photocurrent guiding and absorption enhancement. Finite difference time domain and finite element methods are utilized to obtain optical and electrostatic characteristics of the photodetector. Specifically, responsivity, quantum efficiency, dark current, bandwidth, noise equivalent power (NEP), and specific detectivity (D*) are extracted by employing realistic graphene as well as graphene-metal characteristics. For an optimized device, maximum absorption efficiency is as much as 70% at a wavelength of λ=6.77 µm; however, the peak absorption wavelength can be effectively tuned between λ=6-7 µm. It is shown that increasing the drain-source voltage enhances the responsivity and bandwidth with a side effect of increasing the dark current. Responsivity of the 2×2 photodetector is RA=0.63 AW-1 for V DS =0.5 V with I Dark =350 µA, NEP=16.91 pW/√Hz, and D*=1.53×105 Jones.

Case Report: Pulmonary and Liver Sarcoidosis Suspected of Metastasis.

Introduction: Sarcoidosis is a granulomatous disease with unknown cause that can vary from an asymptomatic condition. Almost half of the patients with sarcoidosis have no symptoms. In this article, we describe a sarcoidosis patient with lung and liver engagement; it may be confused with metastasis. Case report: A 39-year-old man, known as hypothyroidism who had come to the emergency ward with dyspnea and coughing after exposure to detergents in a closed environment A 39-year-old man, known as hypothyroidism who had come to the emergency ward with dyspnea and coughing after exposure to detergents in a closed environment. The patient smoked for 10 years (3 pack/year). No other findings were found in clinical examinations except for wheezing in the right lung. The patient's chest radiography was shown a mass. For further investigation, spiral CT scan was performed. Large lymph nodes on the right side of the trachea, measuring about 23 mm and a mass of 70 × 77 mm in the vicinity of the right lung hilum and a hypodense nodule in the posterior part of the liver with malignancy suspicious were reported. After several biopsy results was shown chronic granulomatous inflammation, the most important differential diagnosis is tuberculosis (TB) and sarcoidosis. Sputum smear, culture, and PCR were performed for tuberculosis. Also, the level of angiotensin-converting enzyme (ACE) was measured for sarcoidosis. the results ruled out TB and shown a higher level of ACE (ACE = 88).After diagnosis treatment started with prednisolone. Now, the patient is in the follow- up. Conclusion: In hilar lymphadenopathy of lung sarcoidosis is the importance differential diagnosis that should be considered.