A Modified Hybrid Brain-Computer Interface Speller Based on Steady-State Visual Evoked Potentials and Electromyogram.

BACKGROUND: To enhance the information transfer rate (ITR) of a steady-state visual evoked potential (SSVEP)-based speller, more characters with flickering symbols should be used. Increasing the number of symbols might reduce the classification accuracy. A hybrid brain-computer interface (BCI) improves the overall performance of a BCI system by taking advantage of two or more control signals. In a simultaneous hybrid BCI, various modalities work with each other simultaneously, which enhances the ITR. METHODS: In our proposed speller, simultaneous combination of electromyogram (EMG) and SSVEP was applied to increase the ITR. To achieve 36 characters, only nine stimulus symbols were used. Each symbol allowed the selection of four characters based on four states of muscle activity. The SSVEP detected which symbol the subject was focusing on and the EMG determined the target character out of the four characters dedicated to that symbol. The frequency rate for character encoding was applied in the EMG modality and latency was considered in the SSVEP modality. Online experiments were carried out on 10 healthy subjects. RESULTS: The average ITR of this hybrid system was 96.1 bit/min with an accuracy of 91.2%. The speller speed was 20.9 char/min. Different subjects had various latency values. We used an average latency of 0.2 s across all subjects. Evaluation of each modality showed that the SSVEP classification accuracy varied for different subjects, ranging from 80% to 100%, while the EMG classification accuracy was approximately 100% for all subjects. CONCLUSIONS: Our proposed hybrid BCI speller showed improved system speed compared with state-of-the-art systems based on SSVEP or SSVEP-EMG, and can provide a user-friendly, practical system for speller applications.

Immunomodulatory activities and biomedical applications of melittin and its recent advances.

Melittin (MLT), a peptide containing 26 amino acids, is a key constituent of bee venom. It comprises ∼40%-60% of the venom's dry weight and is the main pricing index for bee venom, being the causative factor of pain. The unique properties of MLT extracted from bee venom have made it a very valuable active ingredient in the pharmaceutical industry as this cationic and amphipathic peptide has propitious effects on human health in diverse biological processes. It has the ability to strongly impact the membranes of cells and display hemolytic activity with anticancer characteristics. However, the clinical application of MLT has been limited by its severe hemolytic activity, which poses a challenge for therapeutic use. By employing more efficient mechanisms, such as modifying the MLT sequence, genetic engineering, and nano-delivery systems, it is anticipated that the limitations posed by MLT can be overcome, thereby enabling its wider application in therapeutic contexts. This review has outlined recent advancements in MLT's nano-delivery systems and genetically engineered cells expressing MLT and provided an overview of where the MLTMLT's platforms are and where they will go in the future with the challenges ahead. The focus is on exploring how these approaches can overcome the limitations associated with MLT's hemolytic activity and improve its selectivity and efficacy in targeting cancer cells. These advancements hold promise for the creation of innovative and enhanced therapeutic approaches based on MLT for the treatment of cancer.

Early Postoperative Cardiac Complications Following Heart Transplantation:.

Cardiovascular disorders remain the leading cause of death around the world. Heart transplantation is considered the only therapeutic choice defined as the gold standard strategy to manage end-stage heart failure. Nevertheless, the remaining postoperative complications compromise both the survival rate and quality of life in heart transplantation recipients. The present study aimed to review the current findings concerning the main early complications after heart transplantation, reliable predictors, diagnostic approaches, novel surgical techniques, and management strategies. The results demonstrated that significant advances in immunosuppressive pharmaceuticals, determining appropriate policies for donor acceptance, pre and post-operative treatment/care, selection of the most compatible donor with the recipient, and the suggestion of novel diagnostic and surgical techniques over the past decade had dropped the mortality and morbidity rates early after transplantation. However,marrhythmia, atrial flutter, atrial fibrillation, deep sternal wound infection along with other sites infections, low cardiac output syndrome, acute graft dysfunction, pericardial effusion, constrictive pericarditis, and acute cellular rejection could be considered as the major early complications following heart transplantations that pivotally require further investigations.

Human exposure to aerosol from indoor gas stove cooking and the resulting nervous system responses.

Our knowledge of the effects of exposure to indoor ultrafine particles (sub-100 nm, #/cm3 ) on human brain activity is very limited. The effects of cooking ultrafine particles (UFP) on healthy adults were assessed using an electroencephalograph (EEGs) for brain response. Peak ultrafine particle concentrations were approximately 3 × 105 particle/cm3, and the average level was 1.64 × 105 particle/cm3 . The average particle number emission rate (S) and the average number decay rate (a+k) for chicken frying in brain experiments were calculated to be 2.82 × 1012 (SD = 1.83 × 1012 , R2  = 0.91, p = 0.0013) particles/min, 0.47 (SD = 0.30, R2  = 0.90, p < 0.0001) min-1 , respectively. EEGs were recorded before and during cooking (14 min) and 30 min after the cooking sessions. The brain fast-wave band (beta) decreased during exposure, similar to people with neurodegenerative diseases. It subsequently increased to its pre-exposure condition for 70% of the study participants after 30 min. The brain slow-wave band to fast-wave band ratio (theta/beta ratio) increased during and after exposure, similar to observed behavior in early-stage Alzheimer's disease (AD) patients. The brain then tended to return to its normal condition within 30 min following the exposure. This study suggests that chronically exposed people to high concentrations of cooking aerosol might progress toward AD.

Nanotechnology-Abetted Astaxanthin Formulations in Multimodel Therapeutic and Biomedical Applications.

Astaxanthin (AXT) is one of the most important fat-soluble carotenoids that have abundant and diverse therapeutic applications namely in liver disease, cardiovascular disease, cancer treatment, protection of the nervous system, protection of the skin and eyes against UV radiation, and boosting the immune system. However, due to its intrinsic reactivity, it is chemically unstable, and therefore, the design and production processes for this compound need to be precisely formulated. Nanoencapsulation is widely applied to protect AXT against degradation during digestion and storage, thus improving its physicochemical properties and therapeutic effects. Nanocarriers are delivery systems with many advantages─ease of surface modification, biocompatibility, and targeted drug delivery and release. This review discusses the technological advancement in nanocarriers for the delivery of AXT through the brain, eyes, and skin, with emphasis on the benefits, limitations, and efficiency in practice.

Upward spontaneous migration of ventriculoperitoneal shunt into the heart: A case report summary.

A male infant with a history of ventriculoperitoneal (VP) implantation due to congenital hydrocephalus presented with fever and lethargy at the age of 8 month-old. Pericardial effusion was detected in transthoracic echocardiography, and he underwent pericardial window operation and was discharged in a stable condition. At 11 months of age, he presented again with fever, lethargy, recurrent vomiting, and respiratory distress. In both plain chest radiography and transthoracic echocardiography, VP shunt migration to the heart cavity was observed. The VP shunt had entered into the right ventricle after perforating the diaphragm and pericardium. The patient underwent open-heart surgery due to vegetation at the tip of the VP shunt inside the right heart. Vegetation was removed and the tip of the shunt was returned to the peritoneal cavity. Two weeks after discharge, the patient presented again with symptoms of tachypnea and lethargy. The imaging revealed the entry of the VP shunt about two centimeters into the anterior mediastinum. The patient was transferred to the operation room and the VP shunt was shortened and re-inserted into the peritoneal cavity. Antibiotic treatment was continued for six weeks and the patient was discharged in stable condition. In follow-up visits after two years, the VP shunt functioned well and no particular complication was observed. This case demonstrates that in patients with VP shunt implantation presenting with pulmonary and cardiac symptoms such as respiratory distress, pericardial effusion, and cardiac tamponade after VP shunt implantation, the possibility of VP shunt catheter migration to the mediastinal cavity should be considered.

Intranasal administration of immunogenic poly-epitope from influenza H1N1 and H3N2 viruses adjuvanted with chitin and chitosan microparticles in BALB/c mice.

OBJECTIVES: Prevalence of influenza virus, creates the need to achieve an efficient vaccine against it. We examined whether the predicted antigenic epitopes of HA, NP, and M2 proteins of the influenza H1N1 and H3N2 viruses accompanied by chitin and chitosan biopolymers might be relevant to the induction of effective proper mucosal responses. MATERIALS AND METHODS: The construct was prepared using B and T cell predicted epitopes of HA, NP, and M2 proteins from the influenza H1N1 and H3N2 viruses by considering haplotype "d" as a dominant allele in the BALB/c mice. Intranasal immunization with purified LPS free recombinant protein together with chitin and chitosan microparticles as adjuvants was administered at an interval of 2 weeks in thirty-five BALB/c female mice which were divided into seven groups. Ten days after the last immunization, humoral and cellular immune responses were examined. RESULTS: Elevated systemic IgG2a, IgA, and mucosal IgA revealed a humoral response to the construct. An increase in the number of IFN-γ-producing cells in re-stimulation of splenocytes in the culture medium by poly-tope as well as rise in the concentrations of IL-6, IL-17, and TNF-α along with the regulatory response of IL-10, presented the capacity of the designed protein to provoke significant immune responses. The neutralization test ultimately confirmed the high efficacy of the protein in inhibiting the virus. CONCLUSION: The results support the fact that immunogenic poly-tope protein in the presence of chitin and chitosan microparticles as mucosal adjuvants is able to induce humoral and cell-mediated responses in BALB/c mice.

Chitin and chitosan as tools to combat COVID-19: A triple approach.

The progressive and fatal outbreak of the newly emerged coronavirus, SARS-CoV-2, necessitates rigorous collaboration of all health care systems and researchers from all around the world to bring such a devastating pandemic under control. As there is so far no officially approved drug or ideal vaccine for this disease, investigations on this infectious disease are actively pursued. Chitin and chitosan have shown promising results against viral infections. In this review, we first delve into the problematic consequences of viral pandemics followed by an introduction on SARS-CoV-2 taxonomical classification. Then, we elaborate on the immunology of COVID-19. Common antiviral therapies and their related limitations are described and finally, the potential applicability of chitin and chitosan to fight this overwhelming viral pandemic is addressed.

The Empirical Mode Decomposition-Decision Tree Method to Recognize the Steady-State Visual Evoked Potentials with Wide Frequency Range.

BACKGROUND: The empirical mode decomposition (EMD) is a technique to analyze the steady-state visual evoked potential (SSVEP) which decomposes the signal into its intrinsic mode functions (IMFs). Although for the limited stimulation frequency range, choosing the effective IMF leads to good results, but extending this range will seriously challenge the method so that even the combination of IMFs is associated with error. METHODS: Stimulation frequencies ranged from 6 to 16 Hz with an interval of 0.5 Hz were generated using Psychophysics toolbox of MATLAB. SSVEP signal was recorded from six subjects. The EMD was used to extract the effective IMFs. Two features, including the frequency related to the peak of spectrum and normalized local energy in this frequency, were extracted for each of six conditions (each IMF, the combination of two consecutive IMFs and the combination of all three IMFs). RESULTS: The instantaneous frequency histogram and the recognition accuracy diagram indicate that for wide stimulation frequency range, not only one IMF, but also the combination of IMFs does not have desirable efficiency. Total recognition accuracy of the proposed method was 79.75%, while the highest results obtained from the EMD-fast Fourier transform (FFT) and the CCA were 72.05% and 77.31%, respectively. CONCLUSION: The proposed method has improved the recognition rate more than 2.4% and 7.7% compared to the CCA and EMD-FFT, respectively, by providing the solution for situations with wide stimulation frequency range.

Recent Advances in Hybrid Brain-Computer Interface Systems: A Technological and Quantitative Review.

Brain-Computer Interface (BCI) is a system that enables users to transmit commands to the computer using their brain activity recorded by electroencephalography. In a Hybrid Brain-Computer Interface (HBCI), a BCI control signal combines with one or more BCI control signals or with Human-Machine Interface (HMI) biosignals to increase classification accuracy, boost system speed, and improve user's satisfaction. HBCI systems are categorized according to the type of combined signals and the combination technique (simultaneous or sequential). They have been used in several applications such as cursor control, target selection, and spellers. Increasing the number of articles published in this field indicates the significance of these systems. In this paper, different HBCI combinations, their important features, and potential applications are discussed. In most cases, the combination of a BCI control signal with a HMI biosignal yields higher information transfer rate than two BCI control signals.

Electrospun polydimethylsiloxane/polyacrylonitrile/titanium dioxide nanofibers as a new coating for determination of alpha-linolenic acid in milk by direct immersion-solid phase nanoextraction.

In this study, polydimethylsiloxane/polyacrylonitrile/titanium dioxide (PDMS/PAN/TiO2) nanofibers were synthesized via electrospinning method to extract and quantify alpha-linolenic acid (ALA, C18:3), as a model analyte, in milk by direct immersion-solid phase nanoextraction (DI-SPNE) with gas chromatography-flame ionization detector (GC-FID). The affecting factors on the electrospinning process such as, PDMS concentration, amount of TiO2 nanoparticles (NPs), voltage, and electrospinning distance were optimized using Taguchi's orthogonal design. The SPNE experimental conditions such as, extraction time, agitation rate, pH and salt concentration, were also optimized using response surface methodology (RSM) based on a central composite design (CCD). Under optimized conditions, the resulting calibration curve was linear in the range of 1-4000ngmL-1 with R2=0.998. The intraday, interday, and fiber-to-fiber repeatability were calculated and the corresponding relative standard deviation was less than 9% in all the cases. The limit of detection and limit of quantification were found to be 0.2 and 0.6ngmL-1, respectively. Omega-3 enriched milk was used as a real sample and the value of relative recoveries were measured to be in the range of 92-106%.

Effect of IL15 rs10833 and SCARB1 rs10846744 on virologic responses in chronic hepatitis C patients treated with pegylated interferon-α and ribavirin.

The scavenger receptor type B class I (SCARBI) is known to be involved in the entry of hepatitis C virus (HCV) into the host, while interleukin-15 (IL15) is an important cytokine in both the innate and acquired immune responses against HCV infection. We investigated the association of IL15 rs10833 or SCARB1 rs10846744 polymorphisms with treatment responses in patients with chronic HCV (CHC). SCARB1 rs10846744 and IL15 rs10833 were identified in 365 treatment-naïve CHC patients through genotyping by TaqMan® Real-Time PCR and PCR-restriction fragment length polymorphism (RFLP), respectively. Of these 365 CHC treatment-naïve patients, rapid virological response (RVR), complete early virological response (cEVR), and sustained virological response (SVR) were observed in 53.2%, 76.4%, and 66.0% of the patients, respectively. Multivariate logistic regression analysis revealed that RVR was associated with sex (P=0.016), aspartate aminotransferase (AST) (P=0.026), IL15 rs10833 (AA) genotype (P<0.001), and SCARB1 rs10846744 (CC) genotype (P<0.001), while there was a relationship between alanine aminotransferase (ALT) (P=0.013) and IL15 rs10833 (AA) genotype (P<0.001) with cEVR. Age (<40years) (P=0.001), AST (P=0.029), ALP (P=0.028), HCV genotypes (P=0.005), HCV viral load (P=0.026), IL15 rs10833 (AA) genotype (P<0.001), and SCARB1 rs10846744 (CC) genotype (P=0.001) were strongly associated with SVR. In conclusion, the SCARB1 rs10846744 (CC) and IL15 rs10833 (AA) genotypes can be considered as powerful predictors of treatment responses in CHC patients treated with an interferon-based therapy.

Comparison of antigenic sites of the envelope glycoprotein of the Iranian isolate of human T-cell leukemia virus type 1 with different subtypes of the virus.

OBJECTIVE: Human T-cell leukemia virus type 1 (HTLV-1) is an enveloped retrovirus, which is associated with a T-cell malignancy known as adult T-cell leukemia (ATL). Variation in the HTLV-1 envelope nucleotide sequence has been extensively documented and has been used to classify HTLV-1 isolates into different subtypes. The virus occurs in at least 3 subtypes, which have been named A, B, and C. We conducted this study to compare the antigenic proprieties of the Iranian isolate of HTLV-1 with the homologous region of different subtypes of the virus. METHODS: This study took place in the Department of Biology, College of Sciences, Shiraz University, Iran in 2005. The predicted antigenic sites and secondary structure of the envelope glycoprotein of HTLV-1, present in Iran, have been compared with the antigenic sites and secondary structure of the homologous domains in subtypes A, B, C of the virus. To predict the epitopes of glycoproteins, 21 different scales were used. RESULTS: The number of helices in the Iranian isolate was equal to the number of these regions in all 3 subtypes, but the number of beta-sheets was more than other viruses. One potential glycosylation site, on all these studied envelope glycoproteins, was predicted. Antigenic sites in the Iranian isolate were almost similar to subtype A of the virus and the Iranian isolate of HTLV-1 may be belongs to subtype A. CONCLUSION: Our results indicate the similarities and differences between the Iranian and other subtypes of HTLV-1. Antigenic sites represent potential candidates for use in a peptide vaccine against HTLV-1 glycoproteins and since most of the properties of a particular protein depend on its structural properties, this type of study can help in better understanding of HTLV-1 isolates present in Iran.