Ligand-induced incompatible curvatures control ultrathin nanoplatelet polymorphism and chirality.

The ability of thin materials to shape-shift is a common occurrence that leads to dynamic pattern formation and function in natural and man-made structures. However, harnessing this concept to rationally design inorganic structures at the nanoscale has remained far from reach due to a lack of fundamental understanding of the essential physical components. Here, we show that the interaction between organic ligands and the nanocrystal surface is responsible for the full range of chiral shapes seen in colloidal nanoplatelets. The adsorption of ligands results in incompatible curvatures on the top and bottom surfaces of the NPL, causing them to deform into helicoïds, helical ribbons, or tubes depending on the lateral dimensions and crystallographic orientation of the NPL. We demonstrate that nanoplatelets belong to the broad class of geometrically frustrated assemblies and exhibit one of their hallmark features: a transition between helicoïds and helical ribbons at a critical width. The effective curvature [Formula: see text] is the single aggregate parameter that encodes the details of the ligand/surface interaction, determining the nanoplatelets' geometry for a given width and crystallographic orientation. The conceptual framework described here will aid the rational design of dynamic, chiral nanostructures with high fundamental and practical relevance.

Hybrid CdSe/ZnS Quantum Dot-Gold Nanoparticle Composites Assembled by Click Chemistry: Toward Affordable and Efficient Redox Photocatalysts Working with Visible Light.

A new modular, easy-to-synthesize photocatalyst was prepared by assembling colloidal CdSe/ZnS quantum dots (QD) and gold nanoparticles (AuNP) via their ligands thanks to copper-catalyzed azide to alkyne cycloaddition (CuAAC) click chemistry. The resulting composite (QD-AuNP) photocatalyst was tested with a benchmark photoredox system previously reported by our group, for which QD alone acted as a photocatalyst but with a modest quantum yield (QY = 0.06%) and turnover number (TON = 350 in 3 h) due to poor charge separation. After optimization, the QD-AuNP composites exhibited much improved photocatalytic performances: up to five times higher TON (2600 in 3 h) and up to 24 times faster reaction in the first 10 min of visible irradiation. Such an improvement is attributed to an efficient electron transfer from QD to AuNP in the photoexcited QD-AuNP composites, which ensures a much better charge separation than that in QD alone. This was confirmed by studying both (i) the quenching of the QD photoluminescence during the synthesis of the QD-AuNP composites and (ii) the blue shift of the AuNP plasmon absorption band due to the accumulation of up to 7400 electrons per AuNP in QD-AuNP composites under visible light irradiation in the presence of electron donors.

Screening of Breast Cancer from Sweat Samples Analyzed by 2-Dimensional Gas Chromatography-Mass Spectrometry: A Preliminary Study.

Breast cancer (BC) remains one of the most commonly diagnosed malignancies in women. There is increasing interest in the development of non-invasive screening methods. Volatile organic compounds (VOCs) emitted through the metabolism of cancer cells are possible novel cancer biomarkers. This study aims to identify the existence of BC-specific VOCs in the sweat of BC patients. Sweat samples from the breast and hand area were collected from 21 BC participants before and after breast tumor ablation. Thermal desorption coupled with two-dimensional gas chromatography and mass spectrometry was used to analyze VOCs. A total of 761 volatiles from a homemade human odor library were screened on each chromatogram. From those 761 VOCs, a minimum of 77 VOCs were detected within the BC samples. Principal component analysis showed that VOCs differ between the pre- and post-surgery status of the BC patients. The Tree-based Pipeline Optimization Tool identified logistic regression as the best-performing machine learning model. Logistic regression modeling identified VOCs that distinguish the pre-and post-surgery state in BC patients on both the breast and hand area with sensitivities close to 1. Further, Shapley additive explanations and the probe variable method identified the most important and pertinent VOCs distinguishing pre- and post-operative status which are mostly of distinct origin for the hand and breast region. Results suggest the possibility to identify endogenous metabolites linked to BC, hence proposing this innovative pipeline as a stepstone to discovering potential BC biomarkers. Large-scale studies in a multi-centered VOC analysis setting must be carried out to validate obtained findings.

Remote Medical Scent Detection of Cancer and Infectious Diseases With Dogs and Rats: A Systematic Review.

BACKGROUND: Remote medical scent detection of cancer and infectious diseases with dogs and rats has been an increasing field of research these last 20 years. If validated, the possibility of implementing such a technique in the clinic raises many hopes. This systematic review was performed to determine the evidence and performance of such methods and assess their potential relevance in the clinic. METHODS: Pubmed and Web of Science databases were independently searched based on PRISMA standards between 01/01/2000 and 01/05/2021. We included studies aiming at detecting cancers and infectious diseases affecting humans with dogs or rats. We excluded studies using other animals, studies aiming to detect agricultural diseases, diseases affecting animals, and others such as diabetes and neurodegenerative diseases. Only original articles were included. Data about patients' selection, samples, animal characteristics, animal training, testing configurations, and performances were recorded. RESULTS: A total of 62 studies were included. Sensitivity and specificity varied a lot among studies: While some publications report low sensitivities of 0.17 and specificities around 0.29, others achieve rates of 1 sensitivity and specificity. Only 6 studies were evaluated in a double-blind screening-like situation. In general, the risk of performance bias was high in most evaluated studies, and the quality of the evidence found was low. CONCLUSIONS: Medical detection using animals' sense of smell lacks evidence and performances so far to be applied in the clinic. What odors the animals detect is not well understood. Further research should be conducted, focusing on patient selection, samples (choice of materials, standardization), and testing conditions. Interpolations of such results to free running detection (direct contact with humans) should be taken with extreme caution. Considering this synthesis, we discuss the challenges and highlight the excellent odor detection threshold exhibited by animals which represents a potential opportunity to develop an accessible and non-invasive method for disease detection.

Volatile Organic Compounds Analysis as a Potential Novel Screening Tool for Breast Cancer: A Systematic Review.

Introduction: An early diagnosis is crucial in reducing mortality among people who have breast cancer (BC). There is a shortfall of characteristic early clinical symptoms in BC patients, highlighting the importance of investigating new methods for its early detection. A promising novel approach is the analysis of volatile organic compounds (VOCs) produced and emitted through the metabolism of cancer cells. Methods: The purpose of this systematic review is to outline the published research regarding BC-associated VOCs. For this, headspace analysis of VOCs was explored in patient-derived body fluids, animal model-derived fluids, and BC cell lines to identify BC-specific VOCs. A systematic search in PubMed and Web of Science databases was conducted according to the PRISMA guidelines. Results: Thirty-two studies met the criteria for inclusion in this review. Results highlight that VOC analysis can be promising as a potential novel screening tool. However, results of in vivo, in vitro and case-control studies have delivered inconsistent results leading to a lack of inter-matrix consensus between different VOC sampling methods. Discussion: Discrepant VOC results among BC studies have been obtained, highly due to methodological discrepancies. Therefore, methodological issues leading to disparities have been reviewed and recommendations have been made on the standardisation of VOC collection and analysis methods for BC screening, thereby improving future VOC clinical validation studies.

Frequency and Management of Hemorrhagic Malignant Wounds: A Retrospective, Single-Center, Observational Study.

CONTEXT: The prevalence of bleeding episodes in malignant wounds (MW) is poorly documented, with no distinction between minor and potentially severe bleedings. This affects the quality of care. OBJECTIVES: Assessing the frequency and management of hemorrhagic malignant wounds at Institut Curie hospital, an anti cancer center. METHODS: Retrospective study conducted from the medical records of patients followed up by the Research and Wound Care Unit from Curie Institute (Paris, France), between 2017 and 2018. Patients >18 years of age, seen at least once by the Unit, and with an MW > 10 cm2 were included. RESULTS: Ninety patients were included, 74.4% female and 25.6% male, with a median age of 64 years (32-92). The most frequent etiologies were breast cancer (52.2%), sarcomas (12.2%), squamous cell carcinoma ear, nose and throat (11%), and pelvic cancer (8.9%). The median survival of patients after their first consultation was 5.6 months (95% CI: 4.6-8.4). Minor bleedings were observed in 38.9% of situations. Bleedings were significantly higher in malignant fungating wounds (P < 0.01). They were treated by the application of alginate or nonadherent dressings. The presence of at least one minor bleeding significantly increased the risk of more severe bleedings (P < 0.001). Hemorrhagic episodes were reported in 18.9% of patients, and 2.2% of patients died as a result of these bleeding episodes. Hemorrhages were fully controlled by hemostatic dressings in 70.6% of cases. The appearance of bleeding (minor or hemorrhagic) was significantly associated with survival (P < 0.001). CONCLUSION: MWs with bleedings appear to be associated with a poor prognosis and could be a reason for early palliative care even if the patient's general condition is preserved. Palliative care must incorporate wound care skills to provide the most appropriate solutions to this anxiety-provoking symptom.

Synthesis of 3D Dendritic Gold Nanostructures Assisted by a Templated Growth Process: Application to the Detection of Traces of Molecules.

Complex architectures like 3D gold dendritic nanostructures were synthesized by an in situ templated growth method using a thin film of a block copolymer [polystyrene-b-poly(4-vinylpyridine)] deposited onto silicon substrates. The overall study has demonstrated the strong link between the morphology, size, and distribution of the structures and the synthetic physicochemical parameters, such as pH, reaction temperature, concentration, and nature of reactants. A nonequilibirum state of the medium has been required to create a fractal growth of the gold structures onto a prepatterned gold-seeded surface and has led to a better control of the structures' surface coverage rate. Those as-prepared nanodendrites have also exhibited high electrocatalytic activity toward a significant enhancement factor, as well as important sensitivity, thanks to tip effects. The electrochemical experiment results have demonstrated efficient adsorption and quantification of very low traces of specific molecules like glutathione or hexadecanethiol.

Acellular fish skin matrix on thin-skin graft donor sites: a preliminary study.

OBJECTIVE: Surgery for head and neck cancer often requires free flap reconstructions, whose harvesting site often requires a thin-skin graft. Wounds from the thin-skin donor site are comparable to an intermediate or deep second-degree burn. This is uncomfortable and can lead to complications such as a long healing time, local infections and pain. Since they are reproducible, these wounds may serve as a model for an objective assessment of new healing medical devices. The acellular fish skin matrix is a new medical device designed to improve healing quality and time. METHODS: We compared the outcomes between standard procedure and the use of this matrix placed on the split-thickness skin graft (STSG) donor site, in patients operated on in our centre for radial forearm free flap reconstruction for head and neck wounds. RESULTS: There were 21 patients included. The healing time was halved when using the acellular fish skin matrix, from 68 to 32 days on average. Acellular fish skin matrix reduced pain levels and local infection. The visual analogue pain scale (VAS) was ≥3 at five days (p=0.0034) and infection rate reduced from 60% to 0% (p=0.0039). CONCLUSION: These results are extremely encouraging. However, it is important to take into account the relatively high cost of this matrix for its future indications. A larger study including an overall cost estimation and an assessment on different wound types would be interesting, to better target the indications of the acellular fish skin matrix.

A New Transcutaneous Method for Breast Cancer Detection with Dogs.

We developed a new transcutaneous method for breast cancer detection with dogs: 2 dogs were trained to sniff skin secretion samples on compresses that had been worn overnight by women on their breast, and to recognize a breast cancer sample among 4 samples. During the test, the dogs recognized 90.3% of skin secretion breast cancer samples. This proof-of-concept study opens new avenues for the development of a reliable cancer diagnostic tool integrating olfactory abilities of dogs.

Diagnosis and Management of a Cryptoglandular Actinomycotic Fistula-in-Ano: An Update on 7 New Cases and a Review of the Literature.

PURPOSE: Primary anal actinomycosis of cryptoglandular origin, a rare cause of anal suppurative disease, requires specific management to be cured. The aims of this retrospective study were to describe clinical, morphological, and microbiological features of this entity and to evaluate management practices for new cases observed since 2001. METHODS: This was a retrospective case series conducted at the Diaconesses-Croix Saint-Simon Hospital in Paris. RESULTS: From January 2001 to July 2016, 7 patients, 6 males and 1 female (median, 49 years), presenting with an actinomycotic abscess with a cryptoglandular anal fistula were included for study. The main symptom was an acute painful ischioanal abscess. One patient exhibited macroscopic small yellow granules ("sulfur granules"), another "watery pus" and a third subcutaneous gluteal septic metastasis. All patients were overweight (body mass index ≥ 25 kg/m2). Histological study of surgically excised tissue established the diagnosis. All the patients were managed with a combination of classical surgical treatment and prolonged antibiotic therapy. No recurrence was observed during follow-up, the median follow-up being 3 years. CONCLUSION: Actinomycosis should be suspected particularly when sulfur granules are present in the pus, patients have undergone multiple surgeries or suppuration has an unusual aspect. Careful histological examination and appropriate cultures of pus are needed to achieve complete eradication of this rare, but easily curable, disease.

A new method to measure mechanics and dynamic assembly of branched actin networks.

We measured mechanical properties and dynamic assembly of actin networks with a new method based on magnetic microscopic cylinders. Dense actin networks are grown from the cylinders' surfaces using the biochemical Arp2/3-machinery at play in the lamellipodium extension and other force-generating processes in the cell. Under a homogenous magnetic field the magnetic cylinders self-assemble into chains in which forces are attractive and depend on the intensity of the magnetic field. We show that these forces, from piconewtons to nanonewtons, are large enough to slow down the assembly of dense actin networks and controlled enough to access to their non linear mechanical responses. Deformations are measured with nanometer-resolution, well below the optical resolution. Self-assembly of the magnetic particles into chains simplifies experiments and allows for parallel measurements. The combination of accuracy and good throughput of measurements results in a method with high potential for cell and cytoskeleton mechanics. Using this method, we observed in particular a strong non linear mechanical behavior of dense branched actin networks at low forces that has not been reported previously.

Prospective Single-Center Observational Study of Routine Histopathologic Evaluation of Macroscopically Normal Hemorrhoidectomy and Fissurectomy Specimens in Search of Anal Intraepithelial Neoplasia.

BACKGROUND: The necessity for routine histopathologic evaluation of hemorrhoidectomy specimens considered free of suspicious areas after careful visual and manual inspection remains controversial. OBJECTIVE: The purpose of this work was to prospectively study the prevalence of anal intraepithelial neoplasia in macroscopically normal operative specimens. DESIGN AND PATIENTS: From October 2005 to September 2010, all hemorrhoidectomy and fissurectomy specimens were sent for routine histopathologic analysis. SETTING: This study was conducted at a tertiary referral center. MAIN OUTCOME MEASURES: The primary outcome measured was the histopathologic examination of surgical samples. RESULTS: Among the specimens from 2997 procedures, routine histopathologic evaluation found anal intraepithelial neoplasia in 97 patients (3.2%), despite the fact that visual and manual inspection had determined that the specimens were free of any suspected anal intraepithelial neoplasia or human papillomavirus-related lesion. The pathological diagnoses for these macroscopically normal specimens were AIN1 in 22 (23%) patients, AIN2 in 48 (49%) patients and AIN3 in 27 (28%) patients, making the prevalence of high-grade and low-grade disease 2.5% (anal intraepithelial neoplasia 2/3) and 0.7% (anal intraepithelial neoplasia 1). LIMITATIONS: This study was limited by being a single-center study. CONCLUSION: This prospective single-center study demonstrated that the prevalence of infraclinical anal intraepithelial neoplasia in macroscopically normal hemorrhoidectomy and fissurectomy specimens is not negligible (3.2% with 2.5% high-grade disease).

Value of cytologic Papanicolaou smears and polymerase chain reaction screening for human papillomavirus DNA in detecting anal intraepithelial neoplasia: comparison with histology of a surgical sample.

BACKGROUND: The performance of cytologic screening and its correlation with histology and polymerase chain reaction (PCR) detection of human papillomavirus (HPV) DNA have not been evaluated in populations with a low prevalence of anal intraepithelial neoplasia (AIN). The objective of the current study was to analyze the significance of abnormal smears relative to the histology and PCR detection of HPV DNA. METHODS: A cytologic smear and a viral sample were taken in 300 consecutive patients undergoing surgery (Milligan-Morgan hemorrhoidectomy and/or fissurectomy) who gave their informed consent. RESULTS: The cytologic smear was normal in 216 of 290 patients (74.5%). Four high-grade and 19 low-grade intraepithelial neoplastic lesions were identified. In 5 patients, high-grade lesions could not be excluded, 30 lesions were of undetermined significance, and there were 16 cellular modifications with a non-neoplastic appearance. The PCR test for HPV was positive in 18.7% of patients, and a high-risk genotype was identified in 63.6% of positive samples. Histologic examination of the surgical samples was normal in 92.3% of patients. The 23 AIN samples were distributed as follows: 13 grade 1 AIN (AIN1), 6 AIN2, and 4 AIN3. The sensitivity of cytologic smears and PCR for detecting AIN was 56% and 60.8%, respectively, and specificity was 77% and 84.5%, respectively. Combining the 2 tests increased sensitivity to 78% but decreased specificity to 68%. CONCLUSIONS: Compared with a large surgical sample, anal cytologic Papanicolaou smears and HPV PCR exhibited sensitivity and specificity that varied, depending on the risk of HPV infection and AIN. Positive HPV DNA screening increased with AIN grade, and high-risk HPV testing was particularly helpful.

Impact of FDG PET/CT in the staging and the follow-up of anal carcinoma.

PURPOSE: The purpose of the study was to assess the diagnostic performance of positron emission tomography/computed tomography and fluorodeoxyglucose (18F) (FDG PET/CT) for the staging and the follow-up of anal carcinoma, and to evaluate the impact of FDG PET/CT on patient management. MATERIALS AND METHODS: Patients with anal carcinoma were referred to our department from October 2004 until July 2008. The diagnostic performance was evaluated on a perexamination basis and on a per-site basis, together with impact of PET/CT on patient management. The standard of truth was histology when available and, in all cases, follow-up data during at least 6 months. RESULTS: Fifty-eight FDG PET/CT performed in 44 patients were analysed­22 for initial staging and 36 during follow-up. The detection rate of non-excised tumours on initial examination was 93%. During post-treatment follow-up, FDG PET/CT had, on a per-examination basis, sensitivity for the detection of persistent or recurrent disease of 93% and specificity of 81%, and on a per-site basis, 86% and 97%, respectively. Its negative predictive value was 94% on a per-examination basis and 98% on a per-site basis. FDG PET/CT had an impact on management in nine patients out of 44 (20%), which was relevant in eight of them (89%). CONCLUSION: FDG PET/CT is an accurate imaging modality in anal cancer. It has an interesting added value during post-treatment follow-up, especially when persistence or recurrence of disease is suspected. Further studies are needed to evaluate whether surveillance by means of FDG PET/CT might have a positive impact on overall survival.

[Nonsurgical treatment of chronic radiation-induced hemorrhagic proctitis]. / Traitement non chirurgical des rectites radiques chroniques hémorragiques.

The incidence of radiation-induced chronic hemorrhagic proctitis is less than 10 to 20%. The onset of this proctitis is delayed relative to the radiation therapy and generally develops from 6 to 24 months later. There are numerous predisposing factors, the most important of which is the radiation therapy dose: risk increases exponentially above 40-45 Gy. Its pathophysiology involves progressive obliterating endarteritis and transmural interstitial fibrosis, which induce chronic ischemia that is irreversible and progressive during the years after radiation therapy. Its diagnosis depends most often on the combination of clinical history and typical endoscopic appearance (congestive mucosa and/or telangiectases). Topical administrative of sucralfate or corticosteroids as well as argon plasma coagulation, with formalin treatment if necessary, provides relief for most patients.

[Cryptoglandular anal fistulas]. / Fistules anales cryptoglandulaires.

Cryptoglandular anal fistulae are the most frequently occurring form of perianal sepsis. Characteristically they have an endoanal primary opening, a fistula track and an abscess and/or an external purulent opening. Antibiotic therapy is not of use in initial management except in special cases. Treatment of an abscess, if present, is required urgently and when possible, consists of its incision under local anaesthesia. Treating the fistula track occurs afterwards and aims to dry up the purulent discharge and avoid recurrence of the abscess by means of surgical fistulotomy. These techniques are very effective in terms of eradication of the problem but there is sometimes a risk of anal incontinence. This explains the increasing interest in sphincter preserving techniques using the advancement of a covering flap of rectal mucosa and the injection of fibrin glue.

Prevalence of anal cytologic abnormalities in a French referral population: a prospective study with special emphasis on HIV, HPV, and smoking.

PURPOSE: Studying anal cytology to detect intraepithelial neoplasia has been demonstrated to be useful in highly selected populations. This study was designed to determine the frequency of abnormal smears in a wide sample of patients consulting for anorectal symptoms. METHODS: An anal smear was proposed during each consultation during a three-month period. RESULTS: A total of 205 patients (112 females) were included. After the consultation, visible condylomas were detected in 12 (6 percent) of the cases. Two hundred three (99 percent) smears were able to be analyzed. No case of high-grade squamous intraepithelial lesion was found. Four cases of low-grade squamous intraepithelial lesion were found, all in HIV patients with a history of condylomatous lesions. Forty smears were interpreted as atypical squamous cells of undetermined significance and 159 were normal. The prevalence in this population of low-grade squamous intraepithelial lesion was 19 percent (4/21) in HIV seropositive males, and 15 percent (4/26) in the case of a past history of condyloma. The factors associated with an abnormal smear (low-grade squamous intraepithelial lesion or atypical squamous cells of undetermined significance) were a history of anal condylomatous lesions (odd ratio, 4.9; range, 2.1-11.5), HIV seropositivity (odd ratio, 4; range, 1.6-9.9), and smoking (odd ratio, 2.1; range, 1.1-11.5). CONCLUSIONS: This work confirms that the frequency of low-grade squamous intraepithelial lesion is raised in HIV-seropositive males and also where there is a history of condyloma, which corroborates the necessity for regular monitoring and screening of these patients at risk. This study also suggests that the use of tobacco is associated with anal cytologic abnormalities.

[Initial pretherapeutic assessment of anal epidermoid carcinoma]. / Bilan préthérapeutique initial du carcinome épidermoïde invasif de l'anus.

Anal epidermoid carcinoma is a rare malignant tumor, comprising less than 5% of all carcinomas of the colon, rectum, and anus. The primary therapy now includes radiotherapy, often in combination with chemotherapy. Radical surgery is now rarely indicated. Therapeutic indications are based on locoregional staging, the presence of visceral metastases and an evaluation of the medical history. Anorectal endosonography is helpful in evaluating locoregional extension. In addition, magnetic resonance imaging, positron emission tomography scanning and inguinal sentinel lymph node procedure should play a role in a more selective approach in patients with anal carcinoma.

Proctalgia fugax: demographic and clinical characteristics. What every doctor should know from a prospective study of 54 patients.

PURPOSE: This prospective study was designed to describe a typical attack of proctalgia fugax. METHODS: Patients were recruited from May 2003 to June 2004. Whatever the reason for consultation, they were systematically asked: "Do you ever suffer intermittent and recurring anorectal pain lasting for at least three seconds?" If the answer was yes, they were interviewed with a questionnaire and had a proctologic examination. The criterion for proctalgia fugax was a positive answer with a negative examination. RESULTS: The study included 1,809 patients. Fifty-four of these patients (3 percent) had proctalgia fugax and 83 percent of them had never sought medical advice for this problem. The mean age was 51 (range, 18-87) years. Thirty-seven patients were females (69 percent). The onset of pain was sudden and without a trigger factor in 85 percent of cases. Attacks occurred in the daytime (33 percent) as well as at night (35 percent). The pain was described as cramping, spasm-like, or stabbing in 76 percent of cases. It did not radiate in 93 percent of cases. There were no concomitant symptoms in 81 percent of cases. Attacks stopped spontaneously in 67 percent of cases. The average duration was 15 minutes (range, 5 seconds to 90 minutes). The average annual number of attacks was 13 (range, 1-180). CONCLUSIONS: Proctalgia fugax affects twice as many females as males at approximately aged 50 years. Commonly the roughly once-monthly attack occurs as a sudden pain with no trigger factor, diurnally as often as nocturnally. The nonradiating cramp, spasm, or stabbing pain, without concomitant symptoms, is most severe on average after 15 minutes and declines spontaneously.