Effective Coupling Model to Treat the Odd-Even Effect on the Current-Voltage Response of Saturated Linear Carbon Chains Single-Molecule Junctions.

The calculation of the electrical charge transport properties of alkanes C n H 2n S 2 with (n = 4-11) was performed to understand the odd-even effect on its current-voltage response. The extended molecule and broadband limit models were used to describe the molecular junction and covalent coupling with the electrodes. It was shown that among the participating molecular orbitals, HOMO and HOMO-1 are the ones with the most charge transport contribution. Moreover, the odd-even effect is caused by the alternation of the eigenvalues of some frontier orbitals as a function of the number of carbons, especially the HOMO that dominates the electrical transport. It could also be noted that when the current is analyzed outside the resonance, the relationship with the number of carbons exponentially decays, confirming the reports in the literature. To the best of our knowledge, a first principle study of the odd-even effect in symmetric systems composed by linear saturated carbon chains covalently coupled to electrodes has not been reported yet.

Charge Transport in Conjugated and Saturated Hydrocarbons: Comparing Ballistic and Cotunneling Contributions.

The comparison between electrical transport in CnH2n+2S2 alkane and CnHn+2S2 alkene (n = 4, 6, 8, 10) is studied by using a generalized Breit-Wigner approach and considering coherent transport mechanisms and eventual changes in the state of charge (i.e., cotunneling processes) for both molecules. In general, the conductance of alkanes tends to be smaller than that of similar-sized alkenes. However, cotunneling processes have an important participation in the overall transport in the case of alkanes but not for the alkene family. The progressive changes in both the eigenenergies of the relevant frontier molecular orbitals of the charged species and their spatial localization play decisive roles in the observed differences. While the molecular orbitals of the charged species of the conjugated molecules are hardly affected by the applied voltage, their saturated counterparts are quite sensitive to the external field. With this, successive avoided-crossing events between the molecular orbitals of the single-charged alkane molecules can lead to the appearance of nonballistic conduction channels that make no negligible contributions to the molecular transport.

What Cancer Patients Want to Know? Questions from Oncologic Patients in a Brazilian Private Cancer Center.

To establish the more relevant questions oncologic patients may have during cancer treatment. Cross-sectional observational study with all patients undergoing chemotherapy or radiotherapy for cancer in a Brazilian health institution. A questionnaire with open and close questions about cancer diagnosis, treatment, and prognosis was applied. A total of 198 patients were evaluated of whom 122 (62%) were female and 80% of the patients were between 50 and 89 years old. Sixty-one percent of women and 62% of men had questions about cancer diagnosis and treatment. Although questions about nutrition were the most frequent for all patients (72% of men and 48% of women), treatment short- and long-term consequences were a concern for 31% of men and treatment effects on esthetics for 21% of women. After having been informed by the oncology team about their diagnosis and treatment, 49% of the patients also searched for other sources of information. Thirty-eight patients (20%) searched for alternative treatments for cancer. About half of the patients searched for other sources of information after having been informed by the oncology team about their cancer diagnosis and treatment. The present study reinforces the importance for the oncologic health team to spend sufficient time with patients in order to clarify doubts about cancer diagnosis and treatment.

Tailgut cyst adenocarcinoma

Tailgut cysts (TGCs) are rare congenital entities arising from remnants of the embryological postanal primitive gut. Malignancy in TGCs is rare, with the majority being adenocarcinomas and carcinoid tumors. A search of the published literature yielded only 27 cases of adenocarcinoma developing in TGCs. We described the case of a 54-year-old female who presented with complaints of pelvic and perineal pain of several weeks. After the initial work-up, a mass in the right presacral location was diagnosed. She underwent radical resection of the tumor, using a posterior approach. The lesion was removed en bloc with the middle rectum, coccyx, and sacrum (S4­S5). The histopathologic examination revealed an adenocarcinoma arising in a TGC, and the patient received adjuvant chemoradiotherapy. Our case underlines that diagnosing a TGC is difficult as it is a rare congenital lesion. Clinical examination may be challenging as TGCs present with various symptoms, which can mimic other commonly proctologic disorders. Patients should be referred to a tertiary center with experience in pelvic surgery and must be managed by a multidisciplinary approach to maximize successful treatment. The recommended treatment is surgical excision given the malignant potential of TGCs and their risk of causing local complications.

Tailgut cyst adenocarcinoma.

Tailgut cysts (TGCs) are rare congenital entities arising from remnants of the embryological postanal primitive gut. Malignancy in TGCs is rare, with the majority being adenocarcinomas and carcinoid tumors. A search of the published literature yielded only 27 cases of adenocarcinoma developing in TGCs. We described the case of a 54-year-old female who presented with complaints of pelvic and perineal pain of several weeks. After the initial work-up, a mass in the right presacral location was diagnosed. She underwent radical resection of the tumor, using a posterior approach. The lesion was removed en bloc with the middle rectum, coccyx, and sacrum (S4-S5). The histopathologic examination revealed an adenocarcinoma arising in a TGC, and the patient received adjuvant chemoradiotherapy. Our case underlines that diagnosing a TGC is difficult as it is a rare congenital lesion. Clinical examination may be challenging as TGCs present with various symptoms, which can mimic other commonly proctologic disorders. Patients should be referred to a tertiary center with experience in pelvic surgery and must be managed by a multidisciplinary approach to maximize successful treatment. The recommended treatment is surgical excision given the malignant potential of TGCs and their risk of causing local complications.

Epithelioid Hemangioendothelioma Of The Internal Jugular Vein.

Ephitelioid Hemangioendothelioma (EHE) is a rare type of tumor with vascular and sarcomatous components. There's only another case published of an internal jugular vein (IJV) EHE. A case of a 50 years-old woman with a palpable and pulsatile mass on the left cervical area is reported. Doppler ultrasound and magnetic resonance imaging showed an IVJ' 4 cm mass. Cytology was inconclusive. Surgical treatment was therefore decided and during surgery a mass inside the left IJV, with local nonsuspicious lymph nodes, was confirmed. The mass was resected including a segmental resection of the IJV and one affected tributary vessel. Lymphadenectomy of the adjacent cervical levels was performed. Histologic examination depicted an EHE without metastatic lymph nodes. Tumor was staged as pT1bN0M0 and a multidisciplinary sarcoma group proposed surveillance. Patient remained well, without evidence of disease and without complications in a twenty-four months follow-up period.

Generalized Breit-Wigner treatment of molecular transport: Charging effects in a single decanedithiol molecule.

We examine the relative contribution of ballistic and elastic cotunneling mechanisms to the charge transport through a single decanedithiol molecule linked to two terminal clusters of gold atoms. For this, we first introduced a conceptual model that permits a generalization of the Breit-Wigner scattering formalism where the cation, anion, and neutral forms of the molecule can participate with different probabilities of the charge transfer process, but in a simultaneous manner. We used a density functional theory treatment and considered the fixed geometry of each charge state to calculate the corresponding eigenvalues and eigenvectors of the extended system for different values of the external electric field. We have found that for the ballistic transport the HOMO and LUMO of the neutral species play a key role, while the charged states give a negligible contribution. On the other hand, an elastic cotunneling charge transfer can occur whenever a molecular orbital (MO) of the cation or anion species, even if localized in just one side of the molecule-gold clusters complex, has energy close to that of a delocalized MO of the neutral species. Under these conditions, a conduction channel is formed throughout the entire system, in a process that is controlled by the degree of resonance between the MOs involved. Our results indicate that while different charge transfer mechanisms contribute to the overall charge transport, quantum effects such as avoided-crossing situations between relevant frontier MOs can be of special importance. In these specific situations, the interchange of spatial localization of two MOs involved in the crossing can open a new channel of charge transfer that otherwise would not be available.

Sentinel Node in Oral Cancer: The Nuclear Medicine Aspects. A Survey from the Sentinel European Node Trial.

PURPOSE: Nuclear imaging plays a crucial role in lymphatic mapping of oral cancer. This evaluation represents a subanalysis of the original multicenter SENT trial data set, involving 434 patients with T1-T2, N0, and M0 oral squamous cell carcinoma. The impact of acquisition techniques, tracer injection timing relative to surgery, and causes of false-negative rate were assessed. METHODS: Three to 24 hours before surgery, all patients received a dose of Tc-nanocolloid (10-175 MBq), followed by lymphoscintigraphy. According to institutional protocols, all patients underwent preoperative dynamic/static scan and/or SPECT/CT. RESULTS: Lymphoscintigraphy identified 723 lymphatic basins. 1398 sentinel lymph nodes (SNs) were biopsied (3.2 SN per patient; range, 1-10). Dynamic scan allowed the differentiation of sentinel nodes from second tier lymph nodes. SPECT/CT allowed more accurate anatomical localization and estimated SN depth more efficiently. After pathological examination, 9.9% of the SN excised (138 of 1398 SNs) showed metastases. The first neck level (NL) containing SN+ was NL I in 28.6%, NL IIa in 44.8%, NL IIb in 2.8%, NL III in 17.1%, and NL IV in 6.7% of positive patients. Approximately 96% of positive SNs were localized in the first and second lymphatic basin visualized using lymphoscintigraphy. After neck dissection, the SN+ was the only lymph node containing metastasis in approximately 80% of patients. CONCLUSIONS: Best results were observed using a dynamic scan in combination with SPECT/CT. A shorter interval between tracer injection, imaging, and surgery resulted in a lower false-negative rate. At least 2 NLs have to be harvested, as this may increase the detection of lymphatic metastases.

Sentinel European Node Trial (SENT): 3-year results of sentinel node biopsy in oral cancer.

PURPOSE: Optimum management of the N0 neck is unresolved in oral cancer. Sentinel node biopsy (SNB) can reliably detect microscopic lymph node metastasis. The object of this study was to establish whether the technique was both reliable in staging the N0 neck and a safe oncological procedure in patients with early-stage oral squamous cell carcinoma. METHODS: An European Organisation for Research and Treatment of Cancer-approved prospective, observational study commenced in 2005. Fourteen European centres recruited 415 patients with radiologically staged T1-T2N0 squamous cell carcinoma. SNB was undertaken with an average of 3.2 nodes removed per patient. Patients were excluded if the sentinel node (SN) could not be identified. A positive SN led to a neck dissection within 3 weeks. Analysis was performed at 3-year follow-up. RESULTS: An SN was found in 99.5% of cases. Positive SNs were found in 23% (94 in 415). A false-negative result occurred in 14% (15 in 109) of patients, of whom eight were subsequently rescued by salvage therapy. Recurrence after a positive SNB and subsequent neck dissection occurred in 22 patients, of which 16 (73%) were in the neck and just six patients were rescued. Only minor complications (3%) were reported following SNB. Disease-specific survival was 94%. The sensitivity of SNB was 86% and the negative predictive value 95%. CONCLUSION: These data show that SNB is a reliable and safe oncological technique for staging the clinically N0 neck in patients with T1 and T2 oral cancer. EORTC Protocol 24021: Sentinel Node Biopsy in the Management of Oral and Oropharyngeal Squamous Cell Carcinoma.

[Proposal for recognition of the comfort pattern in clients with pemphigus vulgaris using Fuzzy Logic]. / Proposta de reconhecimento de padrão de conforto em clientes com pênfigo vulgar utilizando a Lógica Fuzzy.

The objective was to propose the use of Fuzzy Logic for recognition of comfort patterns in people undergoing a technology of nursing care because of pemphigus vulgaris, a rare mucocutaneous disease that affects mainly adults. The proposal applied experimental methods, with subjects undergoing a qualitative-quantitative comparison (taxonomy/relevance) of the comfort patterns before and after the intervention. A record of a chromatic scale corresponding to the intensity of each attribute was required: pain, mobility and impaired self-image. The Fuzzy rules established by an inference engine set the standard for comfort in maximum, median and minimum discomfort, reflecting the effectiveness of nursing care. Although rarely used in the area of nursing, this logic enabled viable research without a priori scaling of the number of subjects depending on the estimation of population parameters. It is expected to evaluate the pattern of comfort in the client with pemphigus, before the applied technology, in a personalized way, leading to a comprehensive evaluation.