Investigation of fullerene cluster growth mechanisms by carbon atom addition using classical molecular dynamics.

The mechanisms of carbon sticking reactions to C36 and C-C80 fullerenes were investigated with molecular dynamics simulations (MD) using the Second-generation Reactive Empirical Bond Order (SREBO) and Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) potentials that were specifically optimized for carbon-carbon interactions. Results showed the existence of three possible sticking configurations where the projectile atom can stick either to one, two or three atoms of the target fullerene. They also showed that although the two potentials give similar magnitudes for the sticking cross-sections, they yield fairly different results as far as sticking mechanisms and configurations at thermal collision-energies, i.e., in the range 0.05-0.5 eV, are concerned. While AIREBO, that takes into account the long-range Lennard-Jones interaction, essentially results in a surface-sticking configuration with a single atom of the target fullerene, SREBO potential yields both surface- and two neighbors-sticking (2N-sticking) configurations. The fullerene structure is preserved in the last configuration while it can be recovered by a 2000 K annealing in the former configuration. Results obtained with SREBO eventually showed larger sticking probabilities for C36 as compared with C80. In spite of this, the sticking cross-sections obtained for C80 are similar to or even larger than those obtained for C36 due to the larger size of C80 that compensates for its smaller sticking probabilities.

The journey of cancer patients and the quest to equity: findings from Morocco.

OBJECTIVES: Rapid diagnostic and assessment pathways for cancer patients provide timely and effective care. This study took place in Morocco, where the majority of patients treated in the public sector are diagnosed at an advanced stage. The aim of this study was to determine the duration of different time intervals along the cancer patient pathway and to highlight problem areas so that strategies can be implemented to make the process more equitable and effective. STUDY DESIGN: Cross-sectional study. METHODS: Recently diagnosed cancer patients were recruited from four major oncology centres in Morocco; namely, Marrakech, Casablanca, Rabat, and Fez. A questionnaire survey was administered, including sociodemographic and medical information and questions on access to the oncology centre, beliefs, and opinions on the medical staff. The dates of symptom recognition, assessment, diagnosis referral, biopsy, and treatment initiation were collected. Different time intervals (patient, diagnosis, biopsy, and treatment) were estimated and their determinants were investigated. RESULTS: A total of 812 patients were interviewed. The majority of participants were breast cancer patients. In total, 60% of participants were at stage III-IV. The main facilitators of cancer diagnosis confirmation and treatment initiation were easy access to diagnosis and treatment facilities, financial resources, personal history of cancer, time availability, late stage at diagnosis, advanced age, and private health insurance. The patient interval (i.e., time from symptom recognition to initial healthcare assessment) had a median duration of 30 days. The biopsy and treatment intervals were within the current international recommendations (7 and 28 days, respectively). However, the diagnosis interval (52 days) was twice as long as the recommended timeframes from the UK, Australia, and the World Health Organization (<28 days). CONCLUSIONS: Interval targets should be defined to encourage health systems to be more equitable and effective and to ensure that cancer patients are treated within a defined timeframe.

Ischemic stroke in Morocco: Prehospital delay and associated factors.

OBJECTIVES: This study aimed to estimate prehospital delay and to identify the factors associated with the late arrival of patients with ischemic stroke at the Souss Massa Regional Hospital Center in Morocco. PATIENTS AND METHODS: An observational, prospective, cross-sectional study was conducted from March 2019 to September 2019 in the Souss Massa regional hospital center, which is a public hospital structure. A questionnaire was administered to patients with ischemic stroke and to bystanders (family or others), while clinical and paraclinical data were collected from medical records. Univariate and multivariate logistic regression analyses were used to identify the factors associated with delayed arrival at emergency department. RESULTS: A total of 197 patients and 197 bystanders who fulfilled the criteria for the study were included. The median time from symptom onset to hospital arrival was 6hours (IQR, 4-16). Multiple regression analysis showed that illiteracy (OR 38.58; CI95%: 3.40-437.27), waiting for symptoms to disappear (patient behavior) (OR 11.24; CI95%: 1.57-80.45), deciding to go directly to the hospital (patient behavior) (OR 0.07; CI95%: 0.01-0.57), bystander's knowledge that stroke is a disease requiring urgent care within a limited therapeutic window (OR 0.005; CI95%: 0.00-0.36), and direct admission without reference (OR 0.005; CI95%: 0.00-0.07), were independently associated with late arrival (>4.5hours) of patients with acute ischemic stroke. In addition, illiteracy (OR 24.62; CI95%: 4.37-138.69), vertigo and disturbance of balance or coordination (OR 0.14; CI95%: 0.03-0.73), the relative's knowledge that stroke is a disease requiring urgent care and within a limited therapeutic window (OR 0.03; CI95%: 0.00-0.22), calling for an ambulance (relative's behavior) (OR 0.16; CI95%: 0.03-0.80), distance between 50 and 100km (OR 10.16; CI95%: 1.16-89.33), and direct admission without reference (OR 0.03; CI95%: 0.00-0.14), were independently associated with late arrival (>6hours) of patients with acute ischemic stroke. CONCLUSION: Patient behavior, bystander knowledge and direct admission to the competent hospital for stroke care are modifiable factors potentially useful for reducing onset-to-door time, and thereby increasing the implementation rates of acute stroke therapies.

[Small cell neuroendocrine carcinoma of the vulva]. / Carcinome neuroendocrine à petites cellules de la vulve.

Neuroendocrine small cell carcinoma of the vulva is a rare and aggressive cancer with a pejorative behavior. Because it is rare, there is no consensus to date. We report the fourteenth case of a 52-year-old woman with neuroendocrine small cell carcinoma of the vulva, treated by surgery and combined chemoradiotherapy 46 Gy and cisplatinum-étoposide and adjuvant chemotherapy. Twelve months after the diagnosis, she is alive with no evidence of disease recurrence. A review of the literature on this topic is also presented.

Acetaldehyde removal using an atmospheric non-thermal plasma combined with a packed bed: role of the adsorption process.

This work is an attempt in order to help towards understanding the influence of the adsorption process on the removal of a VOC (acetaldehyde, CH3CHO) using cyclic non thermal plasma (NTP) combined with a packed-bed of a catalyst support, α-Al2O3. In the first part, the results obtained by placing the saturated alumina pellets inside the plasma discharge zone are discussed, in terms of acetaldehyde removal, CO and CO2 production. In the second part, adsorption of CH3CHO, CO, CO2 and O3 was carried out, from single and multicomponent mixtures of the different compounds. The results showed that (i) the adsorption capacities followed the order CH3CHO≫ CO2>CO; (ii) O3 was decomposed on the alumina surface; (iii) CO oxidation occurred on the surface when O3 was present. In the third part, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to follow the alumina surface during acetaldehyde adsorption. DRIFTS measurements demonstrated that besides the bands of molecularly adsorbed acetaldehyde, several absorptions appeared on the spectra showing the intermediate surface transformation of acetaldehyde already at 300K. Finally, the relationship between the adsorption results and the NTP combined with a packed-bed process is discussed.

[Efficacy of first-line radiation for non-resectable carotid paraganglioma]. / Efficacité de la radiothérapie en première intention d'un paragangliome carotidien non résécable.

BACKGROUND: Carotid paragangliomas are rare. Surgical resection is the primary treatment. However, when surgery is impossible, radiation therapy is an alternative potentially enabling local control with less morbidity. We report a case of good local control of an unresectable paraganglioma after external beam radiation. CASE REPORT: A 72-year-old-woman, had a 4-year history of right facial palsy associated with pulsatile tinnitus, episodic ear bleeding and ipsilateral hearing loss. Physical examination revealed a retro-mandibular and sub-mastoid pulsatile mass. Magnetic resonance imaging showed a large carotid paraganglioma involving the temporal bone. Since surgical resection was impossible, our patient was given external beam radiation therapy at a dose of 60 Gy. At 12 months follow-up, local control was good without significant toxicity. CONCLUSION: External beam radiation therapy seems to be a good alternative therapy for local control of carotid paragangliomas if surgical resection is impossible.

[Phyllodes tumors of the breast: analysis of 53 patients]. / Tumeurs phyllodes du sein à propos de 53 cas.

PURPOSE: Phyllode tumors of the breast are fibroepithelial tumors similar to fibroadenomas but with a predominant conjunctive tissue component. These are composed of a connective tissue stroma and epithelial elements. They are rare with an incidence of 0.3-0.9% of all breast neoplasms. The present study demonstrates the recent experiences in diagnosis, therapeutical management and clinical follow-up of this disease. PATIENTS AND METHODS: This is a retrospective study of the experience of the Institut National d'Oncologie (INO, Rabat) from 1998 to 2006. RESULTS: We included 53 patients. Median age was 37.2 years (15-67), tumor size was 1-30cm (median 10.25cm). The histological diagnosis was based on the biopsy in (7.8%) cases and extemporany in 22% cases, distant metastasis occurred in two patients; the treatment consisted of a surgery. The median follow-up was three years. Local recurrence occurred in ten patients. Distant metastasis occurred in two patients and five patients have died. CONCLUSION: The confrontation of our results to the data of the international literature shows that the diagnosis of the phyllodes tumours is histological. The basis of the treatment is surgery. The adjuvant radiotherapy is very important in patients at high risk for local recurrence; chemotherapy has a badly defined place. The prognostic is based on the histological characters of the tissue conjunctive component of these tumours.

Microwave engineering of plasma-assisted CVD reactors for diamond deposition.

The unique properties of CVD diamond make it a compelling choice for high power electronics. In order to achieve industrial use of CVD diamond, one must simultaneously obtain an excellent control of the film purity, very low defect content and a sufficiently rapid growth rate. Currently, only microwave plasma-assisted chemical vapour deposition (MPACVD) processes making use of resonant cavity systems provide enough atomic hydrogen to satisfy these requirements. We show in this paper that the use of high microwave power density (MWPD) plasmas is necessary to promote atomic hydrogen concentrations that are high enough to ensure the deposition of high purity diamond films at large growth rates. Moreover, the deposition of homogeneous films on large surfaces calls for the production of plasma with appropriate shapes and large volumes. The production of such plasmas needs generating a fairly high electric field over extended regions and requires a careful design of the MW coupling system, especially the cavity. As far as MW coupling efficiency is concerned, the presence of a plasma load represents a mismatching perturbation to the cavity. This perturbation is especially important at high MWPD where the reflected fraction of the input power may be quite high. This mismatch can lead to a pronounced heating of the reactor walls. It must therefore be taken into account from the very beginning of the reactor design. This requires the implementation of plasma modelling tools coupled to detailed electromagnetic simulations. This is discussed in section 3. We also briefly discuss the operating principles of the main commercial plasma reactors before introducing the reactor design methodology we have developed. Modelling results for a new generation of reactors developed at LIMHP, working at very high power density, will be presented. Lastly, we show that scaling up this type of reactor to lower frequencies (915 MHz) can result in high density plasmas allowing for fast and homogeneous diamond deposition on up to 160 mm diameter surfaces.

[Central nervous system germinoma: retrospective study of six cases]. / Les germinomes du système nerveux central: étude rétrospective de six cas.

PURPOSE: Retrospective analysis of six patients with intracranial germinoma treated in INO and a literature review. MATERIALS AND METHODS: Six patients were treated from 1993 to 1998, for histologically verified primary intracranial germinoma. Median age was 18 years (range: 14-26 years). All patients received chemo-radiotherapy (4FP + radiotherapy from 30 to 50 Gy). RESULTS: 4 tumours were in complete remission. Two patients have kept non-evolutive residual cyst. Five patients are alive with non-evolutive disease after 15-40 months of follow-up (average: 27 months). One patient was lost to follow-up, 14 months after treatment, without disease. CONCLUSION: The treatment of intracranial germinoma is currently first line chemotherapy followed by low-dose and limited irradiation.

Primary malignant lymphoma of the ovary: an unusual presentation of a rare disease.

Because the outcome of patients with primary ovarian non-Hodgkin's lymphoma (NHL) is controversial, we present the incidental finding of a primary malignant lymphoma of the ovary in a 50-year-old patient. Three and a half years following ablative surgery and adjuvant chemotherapy, the patient is alive and disease free. Ovarian lymphoma is a disease of reportedly poor prognosis. However, many previously reported cases of ovarian lymphoma actually represented ovarian involvement by a more diffuse lymphomatous process. If stringent criteria are used for case selection, true primary ovarian lymphoma is a very rare disease and usually carries a favorable prognosis.