155 research outputs found
Novel Green Micro-Synthesis of Graphene-Titanium Dioxide Nano- Composites with Photo-Electrochemical Properties
Background: Graphene-Titanium dioxide nano-composite forms a very promising material in the field of photo-electrochemical research.
Methods: In this study, a novel environment-friendly synthesis method was developed to produce well-distributed anatase nano-titanium dioxide spherical particles on the surface of graphene sheets. This novel method has great advantages over previously developed methods of producing graphenetitanium dioxide nanocomposites (GTNCs). High calcination temperature 650Ā°C was used in the preparation of nano titanium dioxide, and chemical exfoliation for graphene synthesis and GTNC was performed by our novel method of depositing titanium dioxide nanoparticles on graphene sheets using a Y-shaped micro-reactor under a controlled pumping rate with minimal use of chemicals.
Results: The physiochemical and crystallographic properties of the GTNC were confirmed by TEM, XRD, FTIR and EDX measurements, confirming process repeatability. Spherical nano-titanium dioxide was produced in the anatase phase with very high crystallinity and small particle diameters ranging from 9 nm to 25 nm, also the as prepared graphene (RGO) exhibited minimal flake folding and a high carbon content of 81.28% with a low oxygen-to-carbon atomic ratio of 0.172 and GTNCs produced by our novel method had a superior loading content, a homogeneous distribution and a 96.6% higher content of titanium dioxide particles on the graphene sheets compared with GTNCs prepared with the one-pot method.
Conclusion: For its photoelectrochemical properties, chronoamperometry showed that GTNC sample (2) had a higher peak current of 60 Ī¼A compared with that of GTNC sample (1), which indicates that the separation and transfer of electron-hole pairs are better in the case of GTNC sample (2) and according to the LSV results, the generation of photocurrent in the samples can be observed through multiple on-off cycles, which indicates that the electrodes are stable and that the photocurrent is quite reversible
Comparative Amino Acids Studies on Phac Synthases and Proteases as Well as Establishing a New Trend in Experimental Design
ABSTRACT:Ā A question addressed in this study is: why similar enzymes are classified into different subclasses? As an example, PhaC synthases are classified according to four different classes (I, II, III and IV). To answer this question we proposed that besides the catalytic residues, the overall amino acids (AAs) present are responsible for the differences observed. The AAsā composition affects the structure/function/substrate specificity (SFS) of these enzymes. The differences between the classes in various PhaC synthases and proteases were analysed to support our argument. Homology and phylogenic tree of some selected PhaC synthases of different strains (representing the four classes) were demonstrated. The properties of a specific class of enzyme could not be changed into those of another by changing the catalytic residues. Moreover, these differences could not be detected from the proteinsā 3D structures, despite clear differences at the AAs level. Another question was also addressed: could we benefit from the various existing protein databases in the field of biotechnology? To answer this, we introduced a model for an Experimental Design based on the information in the protein database (for strains available in our lab) regarding their ability to degrade castor oil. Two enzymes in the phenol degradation pathway, phenol 2-monooxygenase and catechol 1,2-dioxygenase, and a lipase enzyme were analysed. These enzymes were screened and analysed according to the BLAST-protein database and BRENDA. The comprehensive enzyme information system compared six strains against each other, including: Pseudomonas aeruginosa, Bacillus subtilis, Bacillus pumilus, Bacillus thuringiensis, Bacillus licheniformis, and Geobacillus stearothermophilus. Only P. aeruginosa proved to have the three required enzymes and was suitable for the production of lipases from castor oil (crude castor oil is usually contaminated with phenol) as indicated by the databases. In addition, in vivo castor oil degradation and in vitro lipase enzyme activity were analysed. The apparent lipase activity was 1070 Units/ml. Therefore, this new strategy is recommended to better understand the SFS as well as for using protein database in an Experimental Design.
ABSTRAK: Kajian ini berkisar mengenai soalan: mengapa enzim yang sama diklassifikasikan kepada subkumpulan yang berbeza? Contohnya sintasis PhaC dikelaskan kepada empat kumpulan berbeza (I, II, III dan IV). Bagi menjawab soalan ini selain hipotesis katalitik residue diperkenalkan, faktor yang bertanggungjawab adalah asid amino (AAs) secara keseluruhannya. Komposisi AAs memberi kesan kepada struktur/fungsi/spesifikasi substrat (SFS) enzim-enzim ini. Perbezaan di antara kumpulan dalam pelbagai sintasis PhaC dan proteases telah dianalisis bagi menyokong hujah ini. Homologi dan asas phylogenic bagi sintasis PhaC tertentu yang berbeza strains (mewakili empat kumpulan) telah ditunjukkan. Sifat-sifat tidak boleh ditukarkan dengan menukarkan katalitik residue dari satu kepada yang lain. Tambahan pula, kelainannya tidak boleh dikesan dari struktur 3D protein, walaupun perbezaan yang nyata pada peringkat AAs. Soalan lain yang berkisar adalah: Adakah kita mendapat faedah dari pelbagai pengkalan data dalam bidang bioteknologi? Bagi menjawab soalan ini, model Rekabentuk Eksperimen telah diperkenalkan yang berasaskan maklumat pengkalan data protein bagi strains di makmal kami yang boleh degradasi minyak castor. Dua enzim dalam degradasi fenol telah dianalisis, fenol 2-monooxigenas dan catechol 1,2-dioxygenas serta enzim lipas. Enzim-enzim ini telah disaringkan dan dianalisis dengan merujuk kepada pengkalan data protein-BLAST dan BRENDA. Sistem maklumat enzim secara komprehensif terhadap enam strains termasuk Pseudomonas aeruginosa, Bacillus subtilis, Bacillus pumilus, Bacillus thuringiensis, Bacillus licheniformis dan Geobacillus stearothermophilus. Hanya P. Aeruginosa terbukti mempunyai tiga enzim dan sesuai bagi penghasilan lipase dari minyak kastor (minyak kastor mentah selalunya tercemar dengan fenol) seperti yang ditunjukkan dari pengkalan data. Degradasi minyak kastor in vivo dan aktiviti enzim lipase in vitro telah dilaksanakan. Aktiviti lipase jelas adalah 1070 Units/ml. Kami mencadangkan menggunakan strategi ini bagi memahami SFS serta pengkalan data protein dalam Rekabentuk Eksperimen.
KEYWORDS: amino acids; model; PhaC synthase; protease; lipase; experimental desig
Paget's disease of the breast in a male with lymphomatoid papulosis: a case report
<p>Abstract</p> <p>Introduction</p> <p>Paget's disease is an eczematous skin change of the nipple that is usually associated with an underlying breast malignancy. Male breast cancer represents only 1-3% of all breast malignancies and Paget's disease remains very rare.</p> <p>Case presentation</p> <p>We present the case of a 67-year-old Caucasian man with lymphomatoid papulosis who was diagnosed with Paget's disease of the nipple and who was treated successfully with surgery alone. We discuss the presentation, investigations, management and pathogenesis of Paget's disease of the nipple.</p> <p>Conclusion</p> <p>The case highlights the need to be vigilant when new skin lesions arise in the context of an underlying chronic skin disorder.</p
FEKALNA INKONTINENCIJA Nova koncepcija: Uloga unutarnjeg analnog sfinktera pri defekaciji i fekalnoj inkontinenciji
Introduction. Fecal incontinence is involuntary escape of stool, mucus and/or flatus.Its causes are: anal sphincter damage (childbirth trauma, surgical trauma.); constipation; diarrhea; rectocele; rectal prolapse and rarely congenital causes. Fecal material entering the rectum is evacuated by defecation during which: 1. The smooth muscles of the distal colon and rectum contract, propelling the feces into the anal canal; 2.The anal sphincter relaxes allowing defecation to occur. We put forward a recent concept on the patho-physiology of defecation.The mechanism of defecation has two stages: first stage: (in early childhood) before training; second stage is after training. The mother starts to teach her child how to control himself. This is gained by maintaining high alpha sympathetic tone at the internal anal sphincter (IAS) keeping it closed all the time till appropriate place and time are available. Wherever appropriate place is available and there is a desire, six neuromuscular actions will occur: 1) the person will lower the acquired high alpha sympathetic tone at the IAS relaxing it opening the anal canal; 2) through the voluntary nervous system (NS) he will widen the ano-rectal angle to bring the anal canal and the rectum on one axis. This is done through the pelvic floor muscles; 3) through, voluntary NS he will also relax the external anal sphincter (EAS); then synergistic actions between the voluntary and autonomic nervous system occur; 4) the abdominal and diaphragmatic muscles contract, increasing the intra- abdominal pressure and forcing the feces through the anal canal (via the voluntary NS); 5) the smooth muscles of the distal colon and rectum contract, propelling the feces into the anal canal (through the autonomic NS); 6) followed by sequential contractions of the three parts of the EAS (deep then superficial and then the subcutaneous parts) that will squeeze the anal canal propelling any residual contents.
Objectives. Imaging of the anal canal by 3-dimension ultrasound (3DUS) in normal women and women suffering from fecal incontinence and from rectocele, to compare the state of the IAS and EAS. Methods. 40 patients with FI were assessed clinically and by imaging using 3DUS, and also 10 normal women not suffering from fecal incontinence (FI) as a control. Results. The anal canal is closed in normal women, with intact IAS. In women suffering from FI the anal canal is wide and open with torn IAS. Conclusion. The internal anal sphincter (IAS) is a collageno-muscular tissue cylinder that surrounds the anal canal innervated by alpha-sympathetic nerve supply from the hypogastric nerves. It is surrounded in its lower part by the EAS which is a striated muscle innervated by the pudendal nerve. Its damage during childbirth causes fecal incontinence, and mending its torn wall restores fecal continence.Uvod. Fekalna inkontinencija (insuficijencija stolice) znaÄi nevoljno bježanje stolice, sluzi i/ili vjetrova. Uzroci su: oÅ”teÄenje sfinktera (pri raÄanju djeteta, kirurÅ”ka trauma), zatvor stolice, proljev; rektokela, ispadanje rektuma, rijetko priroÄeno ispadanje. Stolica ulazi u zavrÅ”no crijevo te iz njega izlazi na sljedeÄi naÄin: 1. Glatki miÅ”iÄi donjeg i zavrÅ”nog dijela debelog crijeva se stežu, potiskujuÄi feces u analni kanal; 2. Analni sfinkter olabavi i omoguÄi da uslijedi defekacija. Predstavljamo svježe shvaÄanje o patofiziologiji defekacije. Mehanizam ima dva razdobkja: prvo razdoblje je rano djetinstvo, bez poduke; drugo razdoblje je nakon poduke. Majka poduÄava svoje dijete kako se kontrolirati. To se postiže visokim alfa simpatiÄkim tonusom unutarnjeg analnog sfinktera, držeÄi ga zatvorenim sve dok se ne ukaže odgovarajuÄe mjesto i vrijeme. Kad se naÄe odgovarajuÄe mjesto, i ako postoji želja, poÄinje Å”est sinergistiÄkih neuromuskularnih aktivnosti: 1) osoba Äe sniziti postojeÄi visoki alfa simpatiÄki tonus unutarnjeg analnoga sfinktera i time otvoriti analni kanal; 2) pomoÄu voljnog živÄanog sustava smanjit Äe ano-rektalni kut i dovesti ih u istu osovinu; to postiže pomoÄu miÅ”iÄa dna zdjelice: 3) voljnim živÄanim sustavom takoÄer Äe omlohaviti vanjski analni sfinkter; tada nastupa sinergistiÄna djelatnost voljnog i autonomnog živÄevlja; 4) trbuÅ”ni i dijafragmalni miÅ”iÄi se stežu, poveÄavaju intraabdominalni tlak te potiskuju feces kroz analni kanal; 5) stežu se glatki miÅ”iÄi debelog crijeva i rektuma te potiskuju feces u analni kanal (autonomnim živÄevljem); 6) slijede segmentalna stezanja sva tri dijela vanjskog sfinktera (dubokog, povrÅ”nog pa potkožnog), koja Äe iz analnog kanala istisnuti sve zaostatke.
Svrha rada. Trodimenzionalnim ultrazvukom prikazati analni kanal u zdravih žena te u onih koje pate od fekalne inkontinencije i rektokele, usporediti njihov unutraÅ”nji i vanjski analni sfinkter. Metode. Analizirano je kliniÄki i 3DUZ-om 40 pacijentica s fekalnom inkompetencijom i usporeÄeno s 10 zdravih žena. Rezultat. Analni kanal je u zdravih žena zatvoren, njihov unutrapnji sfinkter je neoÅ”teÄen. U žena s fekalnom inkompetencijom analni kanal je Å”irok i otvoren te s razderanim sfinkterom. ZakljuÄak. Unutarnji analni sfinkter je kolageno-miÅ”iÄno tkivo oblika cilindra koje okružuje analni kanal, inerviran je alfa-simpatiÄkim živcima iz hipogastriÄkog pleksusa. Unutarnji sfinkter je okružen donjim dijelom vanjskog analnog sfinktera, koji je graÄen od prugastog miÅ”iÄja inerviranog pudendalnim živcem. Njegovo oÅ”teÄenje tijekom raÄanja uzrokuje fekalnu inkontinenciju. Prepravak njegove razderane stijenke uspostavlja fekalnu kontinenciju
KIRURÅ KO LIJEÄENJE STRES URINARNE INKONTINENCIJE, FEKALNE INKONTINENCIJE I VAGINALNOG PROLAPSA NOVOM OPERACIJOM Ā»URETRO-ANO-VAGINOPLASTIKAĀ«
We put forward a novel concept explaining the mechanism of micturition and the factors that control urinary continence. Also, we describe the mechanism of defecation and the factors that control stool continence and prevent fecal incontinence. A weak internal urethral sphincter (IUS) will not withstand sudden rise of intra-abdominal pressure and urine will leak. The weakness of the IUS is mostly due to traumatic rupture of its wall as a result of the huge vaginal distension that happens during prolonged, difficult and multiple frequent labors. So, surgical correction is by exposing that rupture and mending its walls. Also the marked vaginal distension which occurs in labor will cause lacerations in the internal anal sphincter (IAS) which is intimately related to the posterior vaginal wall. The torn weak IAS will cause fecal incontinence (FI). Exposing the torn IAS and mending the torn walls will restore the sphincter strength and fecal continence. Vaginal prolapse occurs as a result of vaginal wall weakness, redundancy and flabbiness subsequent to its marked stretching of its walls during vaginal deliveries. Overlapping the vaginal flaps both in the anterior and posterior vaginal wall, such repair will strengthen the vaginal walls, as if we put a collagenous mesh but instead this is an autologus collagenous mesh. We innovated an operation called Ā»urethro-ano-vagino-plastyĀ« to surgically treat urinary incontinence, fecal incontinence and and vaginal prolapse. Objectives. To describe this novel operation, and assess its results for a follow up period of 24 months. Methods. 134 patients with SUI and FI were assessed. Urethro-ano-vaginoplasty was done, and the results were assessed immediately and for 24 months follow up. Results. 121 (90.3%) gained urinary and fecal continence and remained continent in the follow up period. Conclusion. The internal anal sphincter (IAS) is a collageno-muscular tissue cylinder that surrounds the anal canal innervated by alpha-sympathetic nerve supply from the hypogastric nerves. It is surrounded in its lower part by the EAS which is a striated muscle innervated by the pudendal nerve. Its damage during childbirth causes fecal incontinence and mending the torn walls restores fecal continence.Predstavljena je nova koncepcija o mehanizmu mokrenja i Äimbenicima koji reguliraju mokraÄnu kontinenciju. TakoÄer, opisan je mehanizam defekacije te Äimbenici koji kontroliraju kontinenciju stolice i sprjeÄavaju fekalnu inkontinenciju. Slab unutarnji uretralni sfinkter (IUS) se ne može suprostaviti naglom porastu intraabdominalnog tlaka te Äe mokraÄa bježati. Slabost IUS-a je veÄinom posljedica ozljede njegove stijenke zbog silnog vaginalna Å”irenja koje se zbiva tijekom produljenih, teÅ”lih i uÄestalih raÄanja. KirurÅ”ka korekcija se sastoji u nalaženju prsnuÄa i opskrbi njegove stijenke. Vaginalno Å”irenje tijekom poroda uzrokuje prsnuÄe unutarnjeg analnog sfinktera (IAS), koji je intimno povezan sa stražnjom vaginalnom stijenkom. Oslabljeni i prsnuti IAS uzrokuje fekalnu inkontinenciju (FI). Prikaz prsnutog IAS-a i Å”ivanje njegovih razderanih stijenki uspostavit Äe snagu sfinktera i fekalnu kontinenciju. Vaginalni prolaps nastaje kao posljedica slabosti i mlohavosti vaginalne stijenke te njene proÅ”irenosti, zbog istezanja tijekom vaginalnog raÄanja. Preklapanjem vaginalnih režanja prednje i stražnje stijenke ojaÄava se stijenka, umjesto umjetne mrežice postavljamo vlastitu autolognu kolagenu mrežicu. Izumjeli smo za korekciju urinarne i fekalne inkontinencije te vaginalna prolapsa novu operaciju i nazcvali je Ā»uretro-ano-vagino-plastikaĀ«. Cilj rada je opisati novu operaciju i prosuditi njen uspjeh nakon 24 mjeseca. Metoda. Operirane su 134 bolesnice sa stres urinarnom inkontinencijom i fekalnom inkontinencijom. Rezultati. 121 bolesnica (90,3%) je opet postigla mokraÄnu i fekalnu kontinenciju i zadržala ih tijekom praÄenja. ZakljuÄak. Unutarnji analni sfinkter je kolegano-miÅ”iÄni tkivni cilindar, inerviran alfa-simpatiÄnim živcima iz hipogastriÄkog pleksusa koji okružuje analni kanal. U donjem dijelu je okružen vanjskim sfinkterom koji je popreÄno-prugaste miÅ”iÄne graÄe i inerviran ograncima pudendalnog živca. Njegovo oÅ”teÄenje tijekom raÄanja uzrokuje fekalnu inkontinenciju, a Å”ivanje prsnute stijenke uspostavlja fekalnu kontinenciju
PRIKAZ UNUTRAÅ NJEG SFINKTERA URETRE I VAGINE U ZDRAVIH ŽENA I OBOLJELIH OD STRES INKONTINENCIJE MOKRAÄE I PROLAPSA VAGINE
Introduction. The internal urethral sphincter (IUS) is a cylinder formation that extends from the urinary bladder neck to the urogenital diaphragm. It is composed of a strong collagen sheet with muscle fibers that intermingle with the collagen in the middle of the cylinderās thickness. The strong collagen sheet gives the IUS the high wall tension necessary to create the high urethral pressure. The muscle fibers, innervated by alpha sympathetic nerves (T10-L2) are responsible for closure and opening the urethra. Urinary continence depends on the presence of an intact and strong IUS and of an acquired behavior, gained by learning and training in early childhood, how to maintain a high alpha sympathetic tone at the IUS keeping it closed until there is a need. Normal vagina is a cylinder of collageno-elastic-muscular tissues. Its strong collagen sheet is responsible for keeping it in its normal upward position. Labors cause redundancy and weakness of the vaginal walls with subsequent prolapse and lacerations of the IUS which is intimately overlying the anterior vaginal wall resulting in stress urinary incontinence (SUI). Objectives. To image by 3D-US and MRI the IUS and the vagina; and to examine their histopathology. Methods. Histopathology as well as 3D-US and MR imaging are done. Results. Images show the IUS as a compact tissue cylinder that extends from the bladder neck to the urogenital diaphragm in continent women; IUS is torn in women with SUI. Conclusion. The anterior vaginal wall and the IUS are torn in patients with SUI and with vaginal prolapse. They are intact in continent women.Uvod. UnutraÅ”nji uretralni sfinkter (IUS) je cilindriÄnog oblika, proteže se od vrata mokraÄnog mjegura do urogenitalne dijafragme. Sastoji se od Ävrstog kolagenog sloja s miÅ”iÄnim vlaknima koja su izmijeÅ”ana s kolagenom u sredini debljine cilindra. Jaki kolageni sloj daje IUS-u snažnu napetost stijenke potrebnu da stvori visoki intrauretralni tlak. MiÅ”iÄna vlakna, inervirana alfa simpatiÄnim živcima (Th10-L2) su odgovorna za zatvaranje i otvaranje uretre. Kontinencija mokraÄe ovisi o postojanju intaktnog i jakog IUS-a te o steÄenom ponaÅ”anju, uÄeÄi i vježbajuÄi u ranom djetinjstvu kako održati visoki alfa simpatiÄki tonus IUS-a, držeÄi ga zatvorenim dok je potrebno. Normalna vagina je cilindriÄna cijev kolageno-elastiÄno-miÅ”iÄnog tkiva. Njen jaki kolageni sloj je odgovoran za njen uspravni položaj. Porod uzrokuje suviÅ”ak i slabost vaginalne stijenke s posljediÄnim prolapsom i laceracijom IUS-a, koji intimno prileži prednjoj vaginalnoj stijenci, Å”to rezultira stresnom mokraÄnom inkontinencijom (SUI). Cilj istraživanja. Prikazati trodimenzionalnim ultrazvukom (3D-UZ) i magnetskom rezonancijom (MR) te histopatoloÅ”kim pregledom intrauretralni sfinkter i vaginu. Metode. HistopatoloÅ”ka tehnika te 3D-UZ i MR prikazi. Rezultati. Prikazi pokazuju IUS kao kompaktni tkivni cilindar koji se proteže od vrata mokraÄnog mjehura do urogenitalne dijafragme u kontinentnih žena; IUS je oÅ”teÄen u žena sa SUI. ZakljuÄak. Prednja vaginalna stijenka i IUS bivaju oÅ”teÄeni (prsnuti) u pacijentica sa SUI i s vaginalnim prolapsom. Oni su intaktni u kontinentnih žena
Does mixing acute medical admissions with burn patients increase infective complications from paediatric thermal injuries?
In the winter of 2005ā2006, the management at our children's hospital elected to admit āoverspillā acute medical admissions to the ward used for plastic surgery and burns for logistical reasons. This study was conducted to assess the effects of that change on the incidence of infective complications in thermally-injured patients. Seventy-three patients were studied, 23 in the sample winter and 50 in the two preceding control winters. The data gathered included days on IV fluids and antibiotics, transfer to the Paediatric Intensive Care Unit (PICU), microbiology and a āseptic signs scoreā ā based on pyrexia, irritability, diarrhoea/vomiting, wound colonization, bacteraemia. The outcomes studied were: the maximum āseptic signs scoreā; patients with a score ā„3; wound colonization; PICU admission; days on antibiotics and IV fluids. A statistically significant increase in patients with septic episodes was demonstrated by an increase in the mean septic signs score (0.66ā1.48, P = 0.044) and the number of patients with a score ā„3 (4ā22%, P = 0.017). Other analysed variables did not reach statistical significance although the raw data suggested a trend. It was concluded that there is an association between mixing acute medical admissions with thermally-injured patients and an increase in the incidence of infective complications in the latter group
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