Finite-size effects on the dynamic susceptibility of CoPhOMe single-chain molecular magnets in presence of a static magnetic field

The static and dynamic properties of the single-chain molecular magnet [Co(hfac)$_2$NITPhOMe] are investigated in the framework of the Ising model with Glauber dynamics, in order to take into account both the effect of an applied magnetic field and a finite size of the chains. For static fields of moderate intensity and short chain lengths, the approximation of a mono-exponential decay of the magnetization fluctuations is found to be valid at low temperatures; for strong fields and long chains, a multi-exponential decay should rather be assumed. The effect of an oscillating magnetic field, with intensity much smaller than that of the static one, is included in the theory in order to obtain the dynamic susceptibility $\chi(\omega)$. We find that, for an open chain with $N$ spins, $\chi(\omega)$ can be written as a weighted sum of $N$ frequency contributions, with a sum rule relating the frequency weights to the static susceptibility of the chain. Very good agreement is found between the theoretical dynamic susceptibility and the ac susceptibility measured in moderate static fields ($H_{\rm dc}\le 2$ kOe), where the approximation of a single dominating frequency turns out to be valid. For static fields in this range, new data for the relaxation time, $\tau$ versus $H_{\rm dc}$, of the magnetization of CoPhOMe at low temperature are also well reproduced by theory, provided that finite-size effects are included.Comment: 16 pages, 9 figure

Transumbilical versus transvaginal retrieval of surgical specimens at laparoscopy: a randomized trial.

Objective We sought to compare transumbilical (TU) and transvaginal (TV) route for retrieval of surgical specimens at laparoscopy. Study design Women scheduled for a laparoscopic resection of an adnexal mass were randomized to have their surgical specimen removed either through a posterior colpotomy (n = 34) or the umbilical port site (n = 32). Group allocation was concealed from patients and bedside clinicians. The primary outcome was postoperative incisional pain assessed by a 10-cm visual analog scale at 1, 3, and 24 hours after surgery. Results TV retrieval caused less postoperative pain than TU specimen extraction at each time point (visual analog scale score at 1 hour: 2.6 \ub1 2.9 vs 1.2 \ub1 2.0, P = .03; at 3 hours: 2.4 \ub1 2.0 vs 1.4 \ub1 2.0, P = .02; and at 24 hours: 1.1 \ub1 1.5 vs 0.5 \ub1 1.4, P = .02). A higher proportion of women in the TU group than in the TV group indicated the umbilicus as the most painful area at 1 and 3 hours postoperatively. Two months after surgery, the participants scored similarly as to their overall satisfaction, cosmetic outcome, and dyspareunia upon resumption of intercourse. Conclusion A TV approach for specimen removal after laparoscopic resection of adnexal masses offers the advantage of less postoperative pain than TU retrieva

57 Alpelisib for recurrent PIK3CA-mutated recurrent cervcial cancer

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Eradication of isolated para-aortic nodal recurrence in a patient with an advanced high grade sorous ovarian carcinoma: our experience and review of literature

Abstract: We report a case report regarding the eradication of isolated lymph-nodal para-aortic recurrence in the aortic region down the left renal vein (LRV) in a patient treated two years earlier in another hospital for a FIGO stage IC2 high-grade serous ovarian carcinoma with a video showing the para-aortic space after eradication of the metastatic tissue. A 66 year-old woman was admitted 24 months after the initial surgical procedure for an increased Ca 125 level and CT scan that revealed a 3 cm para-aortic infrarenal lymph-nodal recurrence that was confirmed by PET/CT scan. A secondary cytoreductive surgery (SCS) with a para-aortic lymph-nodal dissection of the tissue down the LRV and radical omentectomy were performed: during the cytoreduction, the right hemicolon was mobilized. The anterior surface of the inferior vena cava (IVC), aorta and LRV were exposed. The metastatic lymph nodes were detected in the para-ortic space down the proximal part of the LRV and eradicated; an en bloc infrarenal lymph-node dissection from the aortocaval region was performed. The operative time during the surgical procedure was 212 min with a blood loss of 120 mL. No intra- and postoperative complications, including ureteral or vascular injury or renal dysfunction, occurred. At histological examination, three dissected lymph nodes were positive for metastasis, and the patient was discharged five days after laparotomy without side effects and underwent chemotherapy 3 weeks later; after a follow-up of 42 months, no recurrence was detected. In conclusion, secondary debulking surgery can be considered a safe and effective therapeutic option for the management of recurrences, although long-term follow-ups are necessary to evaluate the overall oncologic outcomes of this procedure

On the scent of sexual attraction

A study in the current issue of BMC Biology has identified a mouse major urinary protein as a pheromone that attracts female mice to male urine marks and induces a learned attraction to the volatile urinary odor of the producer. See research article http://www.biomedcentral.com/1741-7007/8/7

Spin canting in a Dy-based Single-Chain Magnet with dominant next-nearest neighbor antiferromagnetic interactions

We investigate theoretically and experimentally the static magnetic properties of single crystals of the molecular-based Single-Chain Magnet (SCM) of formula [Dy(hfac)$_{3}$NIT(C$_{6}$H$_{4}$OPh)]$_{\infty}$ comprising alternating Dy$^{3+}$ and organic radicals. A peculiar inversion between maxima and minima in the angular dependence of the magnetic molar susceptibility $\chi_{M}$ occurs on increasing temperature. Using information regarding the monomeric building block as well as an {\it ab initio} estimation of the magnetic anisotropy of the Dy$^{3+}$ ion, this anisotropy-inversion phenomenon can be assigned to weak one-dimensional ferromagnetism along the chain axis. This indicates that antiferromagnetic next-nearest-neighbor interactions between Dy$^{3+}$ ions dominate, despite the large Dy-Dy separation, over the nearest-neighbor interactions between the radicals and the Dy$^{3+}$ ions. Measurements of the field dependence of the magnetization, both along and perpendicularly to the chain, and of the angular dependence of $\chi_{M}$ in a strong magnetic field confirm such an interpretation. Transfer matrix simulations of the experimental measurements are performed using a classical one-dimensional spin model with antiferromagnetic Heisenberg exchange interaction and non-collinear uniaxial single-ion anisotropies favoring a canted antiferromagnetic spin arrangement, with a net magnetic moment along the chain axis. The fine agreement obtained with experimental data provides estimates of the Hamiltonian parameters, essential for further study of the dynamics of rare-earths based molecular chains.Comment: 11 pages, 8 figure

Molecular markers and endometrial cancer

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