DESIGN OF HIGHLY STABLE LOW-DENSITY SELF-ASSEMBLED MONOLAYERS USING THIOL-YNE CLICK REACTION FOR THE STUDY OF PROTEIN-SURFACE INTERACTIONS

Protein adsorption on solid surfaces is a common yet complicated phenomenon that is not fully understood. Self-assembled monolayers have been utilized in many studies, as well-defined model systems for studying protein-surface interactions in the atomic level. Various strategies, including the use of single component SAMs[1, 2], combinations of long and short alkanethiolates with methyl- and hydroxyl- terminal groups[3, 4], and using mixtures of alkanethiolates with similar chain length and varying terminal functional group [5] have been used to effectively control the surface wettability and determine the effect of surface composition and wettability on protein adsorption. In this dissertation we report key new findings on the effect of surface density of functional groups on protein adsorption phenomenon. In The first phase of this research, we developed a novel approach for preparation of low-density self-assembled monolayers(LD-SAMs) on gold surfaces, based on radical-initiated thiol-yne click chemistry. This approach provides exceptional adsorbate stability and conformational freedom of interfacial functional groups, and is readily adapted for low-density monolayers of varied functionality. The resulting monolayers have two distinct phases: a highly crystalline head phase adjacent to the gold substrate, and a reduced density tail phase, which is in contact with the environment. First, we investigated the feasibility of the proposed chemistry in solution-phase. In this approach, we synthesized “Y” shaped carboxylate-terminated thiol adsorbates via radical-initiated thiol-yne reaction. The LD-SAMs were then prepared through immersion of gold substrates into the solution of synthesized adsorbate molecules in hexane. The chemical structuring and electrochemical properties of resultant LD-SAMs were analyzed and compared with those of analogous traditional well-packed monolayers, using techniques such as Fourier transform infrared spectroscopy, ellipsometry, electrochemical impedance spectroscopy, reductive desorption, and contact angle goniometry. Characterization results indicated that resulting LD-SAMs have a lower average crystallinity, and higher electrochemical stability compared to well-packed monolayers. In addition, using a three-electrode system, we were able to show a reversible change in LD-SAM surface wettability, in response to an applied voltage. This remodeling capacity confirms the low density of the surface region of LD-SAM coatings. The second area of work was focused on using the developed chemistry in solid-phase. The solid-phase approach minimized the required synthesis steps in solution-phase method, and used the photo-initiated thiol-yne click-reaction for grafting of acid-terminated alkynes to thiol-terminated monolayers on a gold substrate to create similar LD-SAMs as what were prepared through solution-phase process. We characterized the resulting monolayers and compared them to analogous well-packed SAMs and the also low-density monolayers prepared through the solution phase approach. The results confirmed the proposed two-phase structure, with a well-packed phase head phase and a loosely-packed tail phase. In addition, the electrochemical studies, indicated that the resultant monolayers were less stable than the monolayers prepared via solution-phase, but they are yet significantly more stable than typical well-packed monolayers. The less stability of these monolayers were attributed to the partial desorption of adsorbates from the gold substrate due to UV irradiation during the grafting process. Building on the established chemistry, we studied the effect of lateral packing density of functional groups in a monolayer on the adsorption of Bovine serum albumin protein. we used surface plasmon resonance spectroscopy (SPR) and spectroscopic ellipsometry, to evaluate BSA adsorption on carboxylate‑, hydroxyl-, or alkyl- terminated LD-SAMs. It was found that for the LD-SAMs, the magnitude of protein adsorption is consistently higher than that of a pure component, well-packed SAM for all functionalities studied. In addition, it was seen that the magnitude of BSA adsorption the LD-SAMs, was consistently higher than that of a pure component, well-packed SAM for all functionalities studied. The difference of protein adsorption on LD-SAMs and SAMs can not be associated to difference in lateral packing density, unless we eliminate the impact of other contributing factors in protein adsorption such as surface energy. In order to better understand the impact of packing density on protein-surface interactions, we prepared the mixed SAMs of (carboxylate/alkyl) and (hydroxyl/alkyl) with matching surface energy as the carboxylate and hydroxyl terminated LD-SAMs. It was found that the energy-matched mixed SAMs of carboxylate and hydroxyl functionality adsorbed more protein than the LD-SAMs. However, an opposite trend was seen for the alkyl surfaces, where surface energies are comparable for LD-SAMs and pure component SAMs, indicating that BSA proteins have higher affinity for methyl- terminated LD-SAMs than well-packed SAMs

Design and manufacturing of dimensionally controlled graphene based hybrid structures by core-shell electrospinning for energy storage systems

In the first part of study, two-dimensional (2D) graphene oxide sheets were converted into three forms of fibers, foam, and spheres by using different carrying polymers through one-step core-shell electrospraying/electrospinning technique. In this work, graphene-based foam was produced for the first time by utilizing core-shell electrospraying technology instead of available chemical vapor deposition techniques. Electrospraying/electrospinning prevents the aggregations and crumbling of graphene sheets by constructing interconnected framework and provides homogeneous dispersion of graphene sheets in polymer solution under electric field. The proper polymer concentration and solution viscosity were determined by using Mark-Houwink-Sakurada equation. Morphology and dimension of the structures were controlled by tailoring solution and process parameters. Moreover, hollowness of the fabricated 3D graphene-based spheres was altered by changing the core solvent during process. In the second part, platinum (Pt) decorated graphene-based spheres, foam, and fibers were prepared as electrodes via core-shell electrospinning/electrospraying technique followed by reduction and carbonization process. The effect of morphology and dimension of graphene-based carbon electrodes on the electrochemical behavior of electrodes were investigated by cyclic voltammetry and galvanostatic charge-discharge methods. Polyacrylonitrile (PAN) polymer was selected as a carrier to increase the interconnections in graphene network and carbon content. Among three different electrodes, Pt supported 3D graphene-based spheres exhibited the highest specific capacitance of 118 F/g at a scan rate of 1 mV/s as well as good cyclic stability owing to its unique structure and small size of Pt particles. On the other hand, Pt-decorated graphene-based fiber showed lowest specific capacitance of 8 F/g at a scan rate of 1 mV/s. In the last part, a novel and hierarchical hybrid electrode was constructed by the addition of manganese oxide and polyaniline (PANI) into the fiber structure to further improve the electrochemical performance of graphene-based fibers. Manganese oxide with its high theoretical specific capacitance and low cost was integrated to the fiber structure during electrospinning. Whereby, at the last step of process, to enhance the electrical conductivity of electrodes, PANI was deposited on the surface of fibers through in-situ polymerization of aniline monomer. In order to fully understand the effect of graphene on the structure and electrochemical performance of electrodes, two types of graphene including thermally exfoliated graphene oxide (TEGO) and graphene nanoplatelet (GNP) were selected based on the number of graphene layers. Among two fabricated electrodes with different graphene sources, GNP/PANI/manganese oxide carbon fibers showed the highest specific capacitance of 454 F/g at a scan rate of 1 mV/s. The mentioned electrode exhibited a high cycling stability whereby only 11% of capacitance lost after 1000 cycles of charging-discharging. High oxygen functional groups of GNP is believed to enhance the interfacial interactions between electrode components by providing an exfoliated structure. This study especially brings a new insight into the fabrication of high-performance hybrid electrodes for energy storage devices

Imported Malaria in an Iraqi Immigrant to Iran: Relevance for the Maintenance of Elimination Status

Background: Effective malaria control strategies require an accurate understanding of the epidemiology of locally transmitted Plasmodium species. Emerging evidence indicates that migrants from malaria endemic regions are at risk of delayed presentation of Plasmodium spp. and malaria infection.Cases Report: We reported a case of P. vivax malaria occurring after arrival in Iran. Patient was originally from Iraq. A 48-year-old male patient who was hospitalized with fever attacks, chills, and headache after arriving from Iraq to Tehran.Conclusion: In this patient, new prevention and screening strategies should be studied and blood safety policies adapted. Thus, ultimate elimination of malaria in Iran will require national malaria control program to adopt policy and practice aimed at all human species of malaria since neighbor country are still face to problem to control of malaria

Applying GMDH artificial neural network to predict dynamic viscosity of an antimicrobial nanofluid

Objective (s): Artificial Neural Networks (ANN) are widely used for predicting systems’ behavior. GMDH is a type of ANNs which has remarkable ability in pattern recognition. The aim the current study is proposing a model to predict dynamic viscosity of silver/water nanofluid which can be used as antimicrobial fluid in several medical purposes.Materials and Methods: In order to have precise model, it is necessary to consider all influential factors. Temperature, concentration and size of nano particles are used as input variables of the model. In addition, GMDH artificial neural network is applied to design a proper model. Data for modeling are extracted from conducted experimental studies published in valuable journals. Results: The dynamic viscosity of Ag/water nanofluid is precisely modeled by using GMDH. The obtained values for R-squared is equal to 0.9996 which indicates perfect precision of the proposed model. In addition, the highest relative deviation for the model is 2.2%. Based on the values of these statistical criteria, the model is acceptable and very accurate. Conclusion: GMDH artificial neural network is reliable approach to predict dynamic viscosity of Ag/water nanofluid by using temperature, concentration and size of particles as input data

Izražajnost kalretinina kao biomarkera rizika za metastatski karcinom mliječne žlijezde u pasa

Malignant breast tumors are the most common tumors in humans and are associated with a poor prognosis. An accurate animal model of human mammary gland tumorigenesis is needed to test novel diagnosis and treatment strategies. Dogs represent a promising model since they develop such tumors spontaneously. In the present study, three immunomarkers, including calretinin, c-Kit (CD117) and placental alkaline phosphatase (Plap), were used and compared with each other, in relation to estrogen and progesterone receptors and HER2 (triple markers), with the intention of malignancy grading. Enhanced expression of calretinin and placental alkaline phosphatase, without immunoreaction to c-Kit in neoplastic cells, is related to high-grade malignancy. Out of 50 tumors, 31 were metastasized, 29 of which (93.5%) were moderately to strongly calretinin positive (P<0.05). However, the results for c-Kit - and Plap+ in metastatic tumors were not reproducible. It may be concluded that calretinin could be introduced as a determinant biomarker in the diagnosis of breast cancer metastasis.Maligni tumori dojke najčešći su tumori u ljudi i povezani su s lošom prognozom. Da bi se testirali novi dijagnostički postupci i terapijske procedure u ljudi, potreban je prikladan životinjski model tumorogeneze mliječne žlijezde. Psi su potencijalno dobar model zbog spontanog razvoja ovakvih tumora. U ovom su istraživanju, s ciljem stupnjevanja malignosti, međusobno uspoređena tri imunomarkera, kalretinin, c-Kit (CD117) i placentalna alkalna fosfataza (Plap), a zatim su isti uspoređeni i s estrogenskim, progesteronskim te HER2 (trostrukim) markerima. Povećanje izražajnosti kalretinina i placentalne alkalne fosfataze, bez imunoreakcije na c-Kit u neoplastičnim stanicama povezano je s visokim stupnjem malignosti. Od 50 tumora, 31 je metastazirao, od kojih je 29 (93,5 %) bilo umjereno do izrazito pozitivno na kalretinin (P < 0,05). Doduše, rezultati za c-Ki ti Plap+ nisu bili ponovljivi. Zaključujemo da bi kalretinin mogao poslužiti kao biomarker u dijagnostici metatstatskog raka dojke

Prenatal and Postnatal Hair Steroid Levels Predict Post-Partum Depression 12 Weeks after Delivery

Within three to six months after delivery, 13%-19% of women suffer from post-partum depression (PPD), understood as a dysfunctional adaptation to the postpartum condition and motherhood. In the present cross-sectional study, we compared the hair steroid levels of women 12 weeks before and after delivery and with or without PPD.; The present study was a cross-sectional study conducted twelve weeks after delivery. At that time, 48 women (mean age: 25.9 years) with PPD and 50 healthy controls (mean age: 25.2 years) completed questionnaires on depressive symptoms. Further, at the same time point, 6 cm lengths of hair strands were taken, providing samples of hair steroids 12 weeks before and 12 weeks after delivery in order to analyze hair steroids (cortisol, cortisone, progesterone, testosterone, and dehydroepiandrosterone (DHEA)).; Compared to those of women without PPD, hair steroid levels (cortisol, cortisone, progesterone) were significantly lower in women with PPD both before and after delivery. Lower prenatal cortisone and progesterone levels predicted higher depression scores 12 weeks after delivery. Lower prenatal levels of cortisol and progesterone and higher levels of DHEA, and postnatal lower levels of cortisol, cortisone, and progesterone, along with higher levels of DHEA predicted PPD-status with an accuracy of 98%.; PPD is associated with blunted hair cortisol, cortisone, and progesterone secretions both pre- and postpartum. Such blunted steroid levels appear to reflect a stress responsivity that is less adaptive to acute and transient stressors. It follows that prenatally assessed low hair cortisol and progesterone levels, along with high DHEA levels, are reliable biomarkers of post-partum depression 12 weeks after delivery

Sociocultural Attitudes towards Appearance, Self-Esteem and Symptoms of Body - Dysmorphic Disorders among Young Adults

Background:; Beauty and an attractive body shape are particularly important during early adulthood, as both are related to greater mating success, positive social feedback, and higher self-esteem. The media may further influence common features of beauty. We tested whether higher body-dysmorphic disorder (BDD) scores were associated with sociocultural attitudes towards appearance. Additionally, we expected that a link between higher BDD scores and higher perceived media pressure would be mediated by lower self-esteem (SE).; Method:; 350 young Iranian adults (mean age: 24.17 years; 76.9% females) took part in the study. Participants completed questionnaires covering sociodemographic data, sociocultural attitudes towards appearances, and SE, while experts rated participants for symptoms of body dysmorphic disorders.; Results:; Higher BDD scores were associated with higher scores for sociocultural attitudes towards appearance, while SE was not associated with BDD or sociocultural attitudes towards appearance. Higher scores for sociocultural attitudes towards appearance and media pressure predicted higher BDD scores, while SE had no influence.; Conclusion:; Among young Iranian adults, sociocultural attitudes towards appearances and BDD scores, as rated by experts', were related, while SE was not. The shared variance between symptoms of BDD and sociocultural attitudes towards appearance was low, suggesting that other factors such as mating and career concerns together with social feedback might be more important in explaining symptoms of body dysmorphic disorders

ANORECTAL DISEASES IN AVICENNA’S “CANON OF MEDICINE”

Although the development of modern medicine has helped us detect and treat diseases better than in the past, especially in the field of surgery; the history of medicine may be a trigger that can help us use neglected aspects of prior knowledge for the advancement of modern-day science. Since historical papers that have specifically focused on anorectal diseases are rare, but those that exist contain brief discussions in this field, the current study aims to present a detailed review of Avicenna’s approach to anorectal diseases. Therefore, we reviewed On the Diseases of the Anus, the 17th chapter of the third volume of the Canon of Medicine written by Avicenna, and compared his views on the classification and diagnosis of, and the approach to anorectal diseases with that of modern proctology. Avicenna discussed in detail about anorectal diseases such as hemorrhoid, fissure, perianal abscess and fistula, rectal prolapse, fecal incontinence, and pruritus ani. In addition, we introduce herbs which Avicenna used to treat these diseases. Our findings show that Avicenna’s views on the classification and diagnosis of, and the approach to anorectal diseases have few fundamental differences with modern medicine. In addition, the pharmacological effects of some of the herbs that were recommended by Avicenna, and are used in current medicine are proven. Thus the Medieval knowledge can be further scientifically investigated to develop new therapeutic options for anorectal diseases.Premda nam je razvoj moderne medicine pomogao bolje negoli je to bilo u prošlosti detektirati i tretirati bolesti, napose u polju kirurgije, povijest bi medicine mogao biti okidač koji nam može pomoći u korištenju zanemarenih aspekata prijašnjeg znanja, a za unapređenje suvremene znanosti. Budući da su povijesni tekstovi koji se usko fokusiraju na anorektalne bolesti rijetki, ali oni koji postoje sadrže kratku diskusiju u polju, ova studija nastoji detaljno prikazati Avicenin pristup anorektalnim bolestima. Zbog toga smo prikazali 17. poglavlje trećeg sveska Avicenina Kanona medicine, „O bolestima anusa“, i usporedili njegove poglede na klasifikaciju i dijagnozu te pristup anorektalnim bolestima s onima moderne proktologije. Avicena je detaljno raspravljao o anorektalnim bolestima kao što su hemoroidi, rascjep (fisura), perianalni apsces i kanal (fistula), rektalni prolaps, fekalna inkontinencija i analni svrbež. U nastavku predstavljamo trave koje je Avicena koristio za tretiranje spomenutih bolesti. Naše istraživanje pokazuje da Avicenini pogledi na klasifikaciju i dijagnozu te pristup anorektalnim bolestima imaju malo fundamentalnih razlika s modernom medicinom. Zatim su dokazani farmakološki efekti nekih trava koje je preporučivao Avicena i koji se koriste u sadašnjoj medicini. Dakle srednjovjekovno znanje može biti dalje znanstveno proučavano za razvijanje novih terapijskih mogućnosti za anorektalne bolest

Oxybutynin reduces sweating in depressed patients treated with sertraline: a double-blind, placebo-controlled, clinical study

Selective serotonin reuptake inhibitors are primarily used in the pharmacological treatment of patients experiencing a major depressive disorder. However, one of the common unwanted effects is excessive sweating or hyperhidrosis. Oxybutynin is an anticholinergic medication which reduces sweating. The aim of this double-blind study was to examine the effect of administration of oxybutynin on subjective sweating in patients treated with sertraline.; A total of 140 patients experiencing a major depressive disorder (mean age 37.69 ± 10.44 years, 86 females [61.4%]) treated with sertraline (mean dose 83 mg/day) were consecutively enrolled in the study, and all reported excessive sweating as a side effect. Thereafter, the patients were randomly assigned to either an oxybutynin 5 mg/day group or to a placebo group. At the beginning and end of the 2-week trial, the patients completed questionnaires related to sweating and medication-related side effects.; Over time, subjective sweating reduced significantly in the treatment group as compared with the control group. Oxybutynin-induced side effects were uncommon. Relative to male patients, female patients reported less subjective sweating.; Administration of oxybutynin successfully reduced excessive sweating in patients experiencing a major depressive disorder and treated with sertraline. However, possible gender effects should be taken into account