Metal-free dual-phase full organic carbon nanotubes/g-C 3 N 4 heteroarchitectures for photocatalytic hydrogen production

Hydrogen generation from water using solar energy has grown into a promising approach for sustainable energy production. Over the last years, graphitic carbon nitrides (g-C3N4, CN), polymers based on the heptazine-group, have been widely applied as photocatalysts for H2 evolution. The poor charge separation efficiency of CN is considered the major drawback. Here, we investigated the effect of coupling CN with different types of carbon nanotubes on the charge transfer properties and the photocatalytic H2 evolution. We used carbon nanotubes (CNTs) of different wall number (single (SWCNTs), double (DWCNTs) and multi-walled (MWCNTs) CNTs) for the development of full-organic CN based composite photocatalysts. Photoactivity was drastically affected by the content but more importantly by the nature of the CNTs. The SWCNTs functionalized CN composites were the most active presenting approximately 2\u20135 times higher H2 evolution than the corresponding DWCNTs and MWCNTs functionalized CN under both solar and pure visible light irradiation. Photoactivity was primarily controlled by the improved electronic properties linked with the abundance and stability of photogenerated charges as evidenced by electron paramagnetic resonance spectroscopy. Transient absorption spectroscopy verified the transfer of reactive electrons from CN to CNTs. CNTs functioned as electron acceptors improving charge separation. The data suggest that charge transfer is inversely proportional to the wall number of the CNTs and that photoactivity is directly controlled by the size at the nanoscale of the CNTs used. In the CNTs/CN nanocomposites, photogenerated electrons are transferred more efficiently from CN when SWCNTs are used, providing more available electrons for H2 production

Ultrasonographic alterations in achilles tendon in relation to parathormone in chronic hemodialysis patients

Bone alterations and soft-tissue calcifications are often encountered in patients with end-stage renal disease and have been comprehensively investigated. Less common musculoskeletal manifestations, such as spontaneous tendon ruptures, have been sporadically reported and their etiology and predisposing factors remain unknown. We therefore underwent a systematic, high-resolution, ultrasonographic evaluation of 118 Achilles tendons in 59 hemodialysis patients and 42 Achilles tendons in 21 age and sex matched healthy controls. All ultrasonographic features were evaluated and compared. Clinical (duration of hemodialysis) and biochemical (serum intact parathormone levels) predictors were correlated to detected tendon abnormalities of the patient cohort. We elected to use ultrasonography to assess the Achilles tendon disease, because of its high accuracy in the diagnosis of various tendon disorders. The anteroposterior diameter of the Achilles tendon exceeded 6 mm at the distal and middle third in 30.5% and 32.2% of patients, respectively. Distorted tendon echostructure was found in 44.1% and calcific foci in 23.7%, while altered peritenon and pain during probe palpation were identified in 35.6% and 11.9% of patients, respectively. In the cohort of healthy controls, no defects were found. Abnormal tendon thickness was significantly more frequent in patients with parathormone levels >300 pg/ml and 6 mm) characterizes patients with parathormone levels outside the recommended range of 150-300 pg/ml.Οι οστικές αλλοιώσεις και οι αποτιτανώσεις των μαλακών μορίων απαντώνται συχνά σε ασθενείς με νεφρική ανεπάρκεια τελικού σταδίου. Υπάρχουν εκτενείς βιβλιογραφικές αναφορές που αφορούν στις κυριότερες εκδηλώσεις της νεφρικής οστεοδυστροφίας ενώ για τις σπανιότερα εμφανιζόμενες, όπως οι αυτόματες ρήξεις τενόντων ανευρίσκονται μόνο μεμονωμένες δημοσιεύσεις, τις περισσότερες φορές δε χωρίς σαφή αιτιολογικό προσδιορισμό. Για το λόγο αυτό μελετήσαμε με την χρήση υπερηχοτομογράφων υψηλής διακριτικής ικανότητας, 118 Αχίλλειους τένοντες 59 αιμοκαθαιρόμενων σασθενών και τα αποτελέσματα τα συγκρίναμε με τα αντίστοιχα που προέκυψαν από την εξέταση, για τα ίδια απεικονιστικά χαρακτηριστικά, 42 Αχιλλείων τενόντων 21ος ατόμων, αντιστοίχου φύλου και ηλικίας που αποτέλεσαν την ομάδα έλεγχου. Αναζητήσαμε κλινικά (έτη αιμοκάθαρσης) και βιοχημικά (επίπεδα ακέραιου μορίου παραθορμόνης ορού) στοιχεία, τα οποία και συσχετίσαμε με τις τενοντιαίες αλλοιώσεις που προέκυψαν στην ομάδα των ασθενών. Επιλέξαμε την χρήση της μεθόδου της υπερηχοτομογραφίας για την υψηλή ακρίβεια που διαθέτει στην ανάδειξη ποικίλων τενοντιαίων αλλοιώσεων. Αύξηση της προσθιοπίσθιας διαμέτρου, μεγαλύτερης των 6mm, στο άπω και μέσο τμήμα του τένοντα ανευρέθηκε αντίστοιχα στο 30,5% και 32,2% των ασθενών. Διαταραχή της ηχοδομής παρουσίασε το 44,1% και αποτιτανώσεις το 23,7%. Αλλοιώσεις του στρώματος πυκνού συνδετικού ιστού που περιβάλει τον τένοντα βρέθηκε στο 35,6% των ασθενών ενώ στην ίδια ομάδα το 11,9% αισθάνθηκε άλγος κατά την δοκιμασία πρόκλησης άλγους. Ουδείς από την ομάδα ελέγχου παρουσίασε υπερηχοτομογραφικά διαπιστούμενες αλλοιώσεις της τενοντιαίας αρχιτεκτονικής. Η ύπαρξη παθολογικής πάχυνσης, πέραν των 6mm, ανευρίσκεται συχνότερα μεταξύ των ασθενών των οποίων τα επίπεδα παραθορμόνης ήταν υψηλότερα των 300 pg/ml ή χαμηλότερα των 150 pg/ml. Διαπιστώσαμε επίσης πως μια μέση διάρκεια αιμοκάθαρσης μεγαλύτερης των 6 ετών σχετίζεται αμεσότερα με την ύπαρξη εκφυλιστικών αλλοιώσεων. Στην μελέτη μας καταλήξαμε στο συμπέρασμα πως υπερηχογραφικά διαπιστούμενες δομικές ανωμαλίες της τενοντιαίας αρχιτεκτονικής παρουσιάζει ποσοστό μεγαλύτερο του 30% των ασθενών με νεφρική ανεπάρκεια τελικού σταδίου, ειδικά δε όταν αυτή συνδυάζεται με μέσο διάστημα παραμονής στην αιμοκάθαρση τα 6 έτη. Παθολογική πάχυνση του τένοντα (>6mm) εμφανίζουν οι τένοντες των ασθενών εκείνων των οποίων τα επίπεδα παραθορμόνης ορού βρίσκονται εκτός του προτεινόμενου ορίου των 150-300 pg/ml

Ibuprofen Induces Reduction of the Proliferation-Seeking Radiotracer Tc-(V)DMSA Uptake in Severe Epithelial Breast Hyperplasia without Atypia

The purpose of this study was to investigate if ibuprofen intake can influence mammary uptake of the proliferation-seeking radiotracer technetium 99m–pentavalent dimercaptosuccinic acid ( 99m Tc-(V)DMSA) in women with severe epithelial and atypical epithelial breast hyperplasia. Eight patients with histologically confirmed severe epithelial breast hyperplasia with ( n = 4) and without atypia ( n = 4) were submitted prospectively to 99m Tc-(V)DMSA scintimammography before and after a 4-week course of 400 mg ibuprofen daily oral intake. Lesion to background ratios 60 minutes postinjection were calculated and compared ( t -test) before and after ibuprofen administration. Prior to ibuprofen, the patients with severe epithelial hyperplasia displayed a significantly higher 99m Tc-(V)DMSA uptake ratio compared to those with atypical epithelial hyperplasia (2.40 ± 0.32 vs 1.67 ± 0.09, respectively; p = .003). They also exhibited a more substantial percent decline in tracer uptake postibuprofen compared to women with atypical epithelial hyperplasia (62.0 ± 7.1 vs 15.0 ± 0.2, respectively; p = .001). Ibuprofen induces significant uptake reduction of the proliferation-seeking radiotracer 99m Tc-(V)DMSA in severe epithelial breast hyperplasia without atypia. This agent could therefore constitute a potential imaging tool for monitoring chemoprophylaxis effectiveness in women at the early stages of malignant transformation

Ibuprofen Induces Reduction of the Proliferation-Seeking Radiotracer 99m

The purpose of this study was to investigate if ibuprofen intake can influence mammary uptake of the proliferation-seeking radiotracer technetium 99m–pentavalent dimercaptosuccinic acid ( 99m Tc-(V)DMSA) in women with severe epithelial and atypical epithelial breast hyperplasia. Eight patients with histologically confirmed severe epithelial breast hyperplasia with ( n = 4) and without atypia ( n = 4) were submitted prospectively to 99m Tc-(V)DMSA scintimammography before and after a 4-week course of 400 mg ibuprofen daily oral intake. Lesion to background ratios 60 minutes postinjection were calculated and compared ( t -test) before and after ibuprofen administration. Prior to ibuprofen, the patients with severe epithelial hyperplasia displayed a significantly higher 99m Tc-(V)DMSA uptake ratio compared to those with atypical epithelial hyperplasia (2.40 ± 0.32 vs 1.67 ± 0.09, respectively; p = .003). They also exhibited a more substantial percent decline in tracer uptake postibuprofen compared to women with atypical epithelial hyperplasia (62.0 ± 7.1 vs 15.0 ± 0.2, respectively; p = .001). Ibuprofen induces significant uptake reduction of the proliferation-seeking radiotracer 99m Tc-(V)DMSA in severe epithelial breast hyperplasia without atypia. This agent could therefore constitute a potential imaging tool for monitoring chemoprophylaxis effectiveness in women at the early stages of malignant transformation

Photocatalytically Active Graphitic Carbon Nitride as an Effective and Safe 2D Material for In Vitro and In Vivo Photodynamic Therapy

Thanks to its photocatalytic property, graphitic carbon nitride (g-C3N4) is a promising candidate in various applications including nanomedicine. However, studies focusing on the suitability of g-C3N4 for cancer therapy are very limited and possible underlying molecular mechanisms are unknown. Here, it is demonstrated that photoexcitation of g-C3N4 can be used effectively in photodynamic therapy, without using any other carrier or additional photosensitizer. Upon light exposure, g-C3N4 treatment kills cancer cells, without the need of any other nanosystem or chemotherapeutic drug. The material is efficiently taken up by tumor cells in vitro. The transcriptome and proteome of g-C3N4 and light treated cells show activation in pathways related to both oxidative stress, cell death, and apoptosis which strongly suggests that only when combined with light exposure, g-C3N4 is able to kill cancer cells. Systemic administration of the mesoporous form results in elimination from urinary bladder without any systemic toxicity. Administration of the material significantly decreases tumor volume when combined with local light treatment. This study paves the way for the future use of not only g-C3N4 but also other 2D nanomaterials in cancer therapy