Sharif Digital Repository

Assessment of respiratory volume is extensively performed in clinical applications in order to assess the cases of respiratory illness and the progression of the respiratory syndromes. Respiratory plethysmography is employed to determine the changes of chest volume to monitor breathing. A wearable respiration measuring system has been introduced to detect volume variations of chests. The system consists of a flexible sensor, stretchable cloth and electrical board. The flexible sensor, which measures electrical voltage produced by extension movements, is installed inside the shirt and nearly contacts the chest. The system can be used everywhere and be self-applied by patients. The main... 

Cardiovascular diseases contribute to one third of the world's mortality and morbidity, therefore early cardiovascular disease diagnosis, treatment and monitoring has become an important market. Ideally, an early diagnosis device will need to be accurate, non-invasive, low cost and operator independent. Interestingly enough, there is a wide range of non-invasive devices available, but each with a different degree of accuracy and ease of use. In this paper, an attempt has been made to review commercially available technologies for non-invasive vascular screening. As stiffness index, reflection index, augmentation index, central aortic pressure are most commonly used to screen for vascular... 

Nanocages (NCs) have emerged as a new class of drug-carriers, with a wide range of possibilities in multi-modality medical treatments and theranostics. Nanocages can overcome such limitations as high toxicity caused by anti-cancer chemotherapy or by the nanocarrier itself, due to their unique characteristics. These properties consist of: (1) a high loading-capacity (spacious interior); (2) a porous structure (analogous to openings between the bars of the cage); (3) enabling smart release (a key to unlock the cage); and (4) a low likelihood of unfavorable immune responses (the outside of the cage is safe). In this review, we cover different classes of NC structures such as virus-like... 

Once in biological fluids, the surface of nanoparticles (NPs) is rapidly covered with a layer of biomolecules (i.e., the "protein corona") whose composition strongly determines their biological identity, regulates interactions with biological entities including cells and the immune system, and consequently directs the biological fate and pharmacokinetics of nanoparticles. We recently introduced the concept of a "personalized protein corona" which refers to the formation of different biological identities of the exact same type of NP after being exposed to extract plasmas from individuals who have various types of diseases. As different diseases have distinct metabolomic profiles and... 

Multi-site photoplethysmography is an optoelectronic technique that measures changes in blood volume associated with cardiac contraction. Photoplethysmogram (PPG) recording enables researchers to study the vascular and hemodynamic properties of human subjects. Currently, there is no commercial system available in the market to perform multi-channel PPG recording. The measurements can be obtained from fingertips, ear lobes and toes due to their low absorption and high degree of vasculature. The main objective of this project is to develop a suitable data compression algorithm for two-channel simultaneous high resolution wireless PPG recording system. MATLAB software was used during the... 

The most prevalent musculoskeletal condition and one of the most disabilities are caused by low back pain. In the low back pain, a large variety of evaluation tools is presented to assess the results of the treatment; therefore, it is important to measure the trunk angle in order to determine the progress during patient's treatment. In this project, we developed a low cost prototype system for flexion-extension movement to measure the angle of the trunk in sagital plane. The system consists of clothing that is stretchable; a Rubbery Ruler sensor (RRs) attached on clothing, data acquisition system. Inertial Magnetic Unit (IMU) sensor installed on spine is used to calibrate the orientation for... 

Assessment of respiratory volume is widely used in clinical application in order to assess the case of respiratory illness, and the progression of the respiratory syndrome. Respiratory plethysmography is used to determine the changes of chest volume to monitor the breathing. A wearable respiration measuring system has been introduced for detection of volume variations of chest. The system consists of a flexible sensor, stretchable cloth and electrical board. The flexible sensor, whose electrical voltage is produced by body movements, is installed inside the shirt and closely contacts the chest. The low frequency components of body movements recorded by the sensor are mainly generated by... 

Development of predictive multi-organ models before implementing costly clinical trials is central for screening the toxicity, efficacy, and side effects of new therapeutic agents. Despite significant efforts that have been recently made to develop biomimetic in vitro tissue models, the clinical application of such platforms is still far from reality. Recent advances in physiologically-based pharmacokinetic and pharmacodynamic (PBPK-PD) modeling, micro- and nanotechnology, and in silico modeling have enabled single- and multi-organ platforms for investigation of new chemical agents and tissue-tissue interactions. This review provides an overview of the principles of designing... 

Particle separation has a variety of applications in biology, chemistry and industry. Among them, circulating tumor cells (CTCs) separation has drawn significant attention to itself due to its high impact on both cancer diagnosis and therapeutics. In recent years, there has been growing interest in using inertial microfluidics to separate micro/nano particles based on their sizes. This technique offers label-free, high-throughput and efficient separation and can be easily fabricated. However, further improvements are needed for potential clinical applications. In this study, a novel inertial separation technique using spiral microchannel having stair-like cross section is introduced. The... 

To date various commercial systems have been used in the GAIT analysis. These systems have some difficulties for clinical use, such as interfering with normal movement and high prices. The possibility of utilization of Kinect as a sensor for GAIT analysis has been studied in this research. The accuracy of Kinect in calculation of GAIT parameters such as lower limb joint angles, stride time, and stride length were computed during normal walking. The effects of the sensor's position and direction relative to the walkway were also investigated. The Kinect sensor was installed at different positions toward the motion path. In each position the data was recorded by both Kinect and a commercial... 

A number of geometrically-detailed passive finite element (FE) models of the lumbar spine have been developed and validated under in vitro loading conditions. These models are devoid of muscles and thus cannot be directly used to simulate in vivo loading conditions acting on the lumbar joint structures or spinal implants. Gravity loads and muscle forces estimated by a trunk musculoskeletal (MS) model under twelve static activities were applied to a passive FE model of the L4-L5 segment to estimate load sharing among the joint structures (disc, ligaments, and facets) under simulated in vivo loading conditions. An equivalent follower (FL), that generates IDP equal to that generated by muscle... 

A number of geometrically-detailed passive finite element (FE) models of the lumbar spine have been developed and validated under in vitro loading conditions. These models are devoid of muscles and thus cannot be directly used to simulate in vivo loading conditions acting on the lumbar joint structures or spinal implants. Gravity loads and muscle forces estimated by a trunk musculoskeletal (MS) model under twelve static activities were applied to a passive FE model of the L4-L5 segment to estimate load sharing among the joint structures (disc, ligaments, and facets) under simulated in vivo loading conditions. An equivalent follower (FL), that generates IDP equal to that generated by muscle... 

Synthetic CT (sCT) generation from MR images is yet one of the major challenges in the context of MR-guided radiation planning as well as quantitative PET/MR imaging. Deep convolutional neural networks have recently gained special interest in large range of medical imaging applications including segmentation and image synthesis. In this study, a novel deep convolutional neural network (DCNN) model is presented for synthetic CT generation from single T1-weighted MR image. The proposed method has the merit of highly accelerated convergence rate suitable for applications where the number of training da-taset is limited while highly robust model is required. This algorithm exploits a Visual... 

Objective: This study aimed to employ nonlinear dynamic approaches to assess trunk dynamic stability with speed, symmetry, and load during repetitive flexion-extension (FE) movements for individuals with and without nonspecific low back pain (NSLBP). Background: Repetitive trunk FE movement is a typical work-related LBP risk factor contingent on speed, symmetry, and load. Improper settings/adjustments of these control parameters could undermine the dynamic stability of the trunk, hence leading to low back injuries. The underlying stability mechanisms and associated control impairments during such dynamic movements remain elusive. Method: Thirty-eight male volunteers (19 healthy, 19 NSLBP)... 

Pain level estimation from videos of face has many benefits for clinical applications. Most of the previous works focused only on pain detection task. However, pain level estimation of video sequences has been discussed fewer. In this work, we have proposed a new regression-based approach to estimate the pain level of video sequences. As the first step, facial expression-related features were extracted from each frame, this task was done by reducing identity-related features using the robust principal component analysis decomposition. Then, we used the minimum, maximum, and mean of the features of frames in a sequence to represent that sequence by a fixed-length feature vector. After this,... 

In this study, novel hydrogel nanoparticles with dual triggerable release properties based on fibrous structural proteins (keratin) and thermoresponsive copolymers (Pluronic) are introduced. Nanoparticles were used for curcumin delivery as effective and safe anticancer agents, the hydrophobicity of which has limited their clinical applications. A drug was loaded into hydrogel nanoparticles by a single-step nanoprecipitation method. The drug-loaded nanoparticles had an average diameter of 165 and 66 nm at 25 and 37 °C, respectively. It was shown that the drug loading efficiency could be enhanced through crosslinking of the disulfide bonds in keratin. Crosslinking provided a targeted release... 

Since most of the anticancer drugs have low solubility in water, the clinical use of them is limited unless by some modification the solubility increases or the drug is carried with a soluble compartment. To solve this problem, we prepared a magnetic nanocarrier with a hydrophobic surface based on oleic acid chains in which hydrophobic drug molecules such as doxorubicin hydrochloride (DOX) and paclitaxel (PTX) are easily adsorbed onto the surface. Since the drug molecules are physically adsorbed on the surface, large amounts of DOX (282 mg·g-1) and PTX (316 mg·g-1) were immobilized onto the nanocarrier. Then, the surface of the drug loaded magnetic core was covered by a smart pH-sensitive... 

Superparamagnetic iron oxide nanoparticles with proper surface coatings are increasingly being evaluated for clinical applications such as hyperthermia, drug delivery, magnetic resonance imaging, transfection, and cell/protein separation. To enhance the applicability of magnetic nanoparticles, two main problems must be overcome. First, as the drug coats the particle surface, a significant portion of it is quickly released upon injection (burst effect). Therefore, only small amounts of the drug reach the specific site after, for example, magnetic drug targeting. Second, once the surface-derivatized nanoparticles are inside the cells, the coating is likely digested, leaving the bare particles... 

The successful clinical application of patient-specific personalized medicine for the management of low back patients remains elusive. This study aimed to classify chronic nonspecific low back pain (NSLBP) patients using our previously developed and validated wearable inertial sensor (SHARIF-HMIS) for the assessment of trunk kinematic parameters. One hundred NSLBP patients consented to perform repetitive flexural movements in five different planes of motion (PLM): 0◦ in the sagittal plane, as well as 15◦ and 30◦ lateral rotation to the right and left, respectively. They were divided into three subgroups based on the STarT Back Screening Tool. The sensor was placed on the trunk of each... 

Carbon-based nanocarriers such as multiwall carbon nanotubes (MWCNTs) and reduced graphene oxide (rGO) have shown promising delivery capabilities due to their low immunogenicity, superior internalization, and suitable cell penetration efficiency. Herein, a molecular engineering strategy is advanced for the one-pot synthesized rGO/MWCNT/Fe3O4/ZnO to enhance the stability of the nanocarrier in the biological matrix; green synthesized ZnO was responsible for water uptake and reduced cytotoxicity, while Fe3O4controlled the cellular internalization for gene delivery. Surface morphology of the ensuing nanocomposite was correlated with photocatalytic and gene delivery (CRISPR/Cas9) features. For...