Time-resolved structural dynamics of the out-of-equilibrium charge density wave phase transition in GdTe3

We use ultrafast electron diffraction to study the out-of-equilibrium dynamics of the charge density wave (CDW) phase transition in GdTe3, a quasi-two-dimensional compound displaying a unidirectional CDW state. Experiments were conducted at different incident fluences and different initial sample temperatures below Tc. We find that following photo-excitation, the system undergoes a non-thermal ultrafast phase transition that occurs in out-of-equilibrium conditions. The intrinsic crystal temperature was estimated at each time delay from the atomic thermal motion, which affects each Bragg peak intensity via the Debye Waller factor. We find that the crystal temperature stabilizes with a 6 ps timescale in a quasi-equilibrium state at temperature T q . e . . We then relate the recovery time of the CDW and its correlation lengths as a function of T q . e . . The charge density wave is suppressed in less than a picosecond while its recovery time increases linearly with incident fluence and initial temperature. Our results highlight that the dynamics is strongly determined by the initial sample temperature. In addition, the transient CDW phase recently observed along the transverse direction in LaTe3 and CeTe3 is not observed in GdTe3.

[The management of nephropathic patients during the Covid-19 pandemic: the experience of Ragusa]

The public emergency caused by Covid-19 has forced health services to reorganize in order to separate positive patients from negative ones. In nephrology, this reorganization involves several levels of assistance concerning hospitalizations, ambulatory care and haemodialysis. Within the Complex Unit of Nephrology in Ragusa, the distribution of nephro-dialytic resources has involved four different hospitals, hence ensuring haemodialysis services for asymptomatic and pauci-symptomatic Covid-19 patients as well as for patients in Covid-Unit, Sub-Intensive Therapy and Intensive Care Unit. In this complex context, we had to create a common protocol involving all the professionals who provide assistance in our Unit, across the different structures. We also report some encouraging data that seem to indicate the effectiveness of the protocols put in place.

SAXS investigations of the morphology of swift heavy ion tracks in α-quartz

The morphology of swift heavy ion tracks in crystalline α-quartz was investigated using small angle x-ray scattering (SAXS), molecular dynamics (MD) simulations and transmission electron microscopy. Tracks were generated by irradiation with heavy ions with energies between 27 MeV and 2.2 GeV. The analysis of the SAXS data indicates a density change of the tracks of ~2 ± 1% compared to the surrounding quartz matrix for all irradiation conditions. The track radii only show a weak dependence on the electronic energy loss at values above 17 keV nm(-1), in contrast to values previously reported from Rutherford backscattering spectrometry measurements and expectations from the inelastic thermal spike model. The MD simulations are in good agreement at low energy losses, yet predict larger radii than SAXS at high ion energies. The observed discrepancies are discussed with respect to the formation of a defective halo around an amorphous track core, the existence of high stresses and/or the possible presence of a boiling phase in quartz predicted by the inelastic thermal spike model.

Ion-induced elongation of gold nanoparticles in silica by irradiation with Ag and Cu swift heavy ions: track radius and energy loss threshold

Systematic investigations of the energy loss threshold above which the irradiation-induced elongation of spherical Au nanoparticles occurs are reported. Silica films containing Au nanoparticles with average diameters of 15-80 nm embedded within a single plane were irradiated with 12-54 MeV Ag and 10-45 MeV Cu ions at 300 K and at normal incidence. We demonstrate that the efficiency of the ion-induced nanoparticle elongation increases linearly with the electronic energy transferred per ion track length unit from the energetic ions to the silica film. Ion beam shaping occurs above a threshold value of the specific electronic energy transfer. Three relevant regions are identified with respect to the original size of the Au nanoparticles. For 15 and 30 nm diameter particles, elongation occurs for electronic stopping power larger than 3.5 keV nm(-1). For Au nanoparticles with 40-50 nm diameter an electronic stopping power above 5.5 keV nm(-1) is required for elongation to be observed. Elongation of Au nanoparticles with 80 nm diameter is observed for electronic stopping between ∼ 7-8 keV nm(-1). For all combinations of ions and energies, the ion track temperature profiles are calculated within the framework of the thermal spike model. The correlation between experimental results and simulated data indicates a thermal origin of the increase in the elongation rate with increasing the track diameter.

Role of thermodynamics in the shape transformation of embedded metal nanoparticles induced by swift heavy-ion irradiation

Swift heavy-ion irradiation of elemental metal nanoparticles (NPs) embedded in amorphous SiO(2) induces a spherical to rodlike shape transformation with the direction of NP elongation aligned to that of the incident ion. Large, once-spherical NPs become progressively more rodlike while small NPs below a critical diameter do not elongate but dissolve in the matrix. We examine this shape transformation for ten metals under a common irradiation condition to achieve mechanistic insight into the transformation process. Subtle differences are apparent including the saturation of the elongated NP width at a minimum sustainable, metal-specific value. Elongated NPs of lesser width are unstable and subject to vaporization. Furthermore, we demonstrate the elongation process is governed by the formation of a molten ion-track in amorphous SiO(2) such that upon saturation the elongated NP width never exceeds the molten ion-track diameter.

GnRH antagonist-induced inhibition of the premature LH surge increases pregnancy rates in IUI-stimulated cycles. A prospective randomized trial

BACKGROUND

Our prospective randomized controlled trial was designed to assess whether the use of GnRH antagonists can improve the success rate of controlled ovarian stimulation (COS)/intrauterine insemination (IUI) treatments, via inhibition of the premature LH rise.

METHODS

A total of 104 patients were randomly divided, using a randomization list, into two groups: in group A (n = 52), recombinant FSH (rFSH) was given with GnRH antagonist Cetrorelix, and in group B (n = 52), the patients received rFSH alone in a manner similar to that of group A. The primary outcome measure was clinical pregnancy rate per couple.

RESULTS

The pregnancy rate per patient was 53.8% in group A and 30.8% in group B (P = 0.017). The rate of premature LH surge was 7% in group A and 35% in group B (P < 0.0001). A premature luteinization was observed in two cycles of 144 in group A (1.4%) and in 16 cycles of 154 in group B (10.4%) (P = 0.001). The mean values of LH and progesterone were significantly lower in patients receiving GnRH antagonist than in those who did not (3.3 +/- 3.3 mIU/ml in group A versus 9.9 +/- 7.9 mIU/ml in group B, P < 0.0001, for LH; 1.3 +/- 1.1 ng/ml versus 2.1 +/- 1.9 ng/ml for group A and B, respectively, P < 0.0001, for progesterone).

CONCLUSION

The use of GnRH antagonist in COS/IUI cycles improves pregnancy rate, preventing the premature LH rise and luteinization.

Incidence of Prostate Cancer in Sicily: Results of a Multicenter Case-Findings Protocol

OBJECTIVE

To establish the incidence of prostate cancer (PCa) in Sicily in patients who entered an early detection protocol.

METHODS

From February 2002 to February 2004, 16,298 subjects aged 40-75 entered the protocol. Patients with suspicious DRE, PSA>10 ng/ml, PSA<or=2.5 ng/ml, from 2.6 to 4 ng/ml or from 4.1 to 10 ng/ml with F/T PSA of <or=15%, <or=20% and <or=25% respectively underwent needle biopsy according to an extensive protocol.

RESULTS

3266 patients were eligible for biopsy; PSA was <or=4 in 12.7% and <or=10 ng/ml in 63.9% of patients. A PCa was found in 1171 cases (36.9%) with a relationship between PCa incidence and PSA and age respectively (chi2-test, p<0.0001); 51.8% of patients with PCa had a PSA<10 and 8.8% a PSA<4 ng/ml; 49% were clinically staged as T1c. The estimated odds ratios for each age group showed increased risk for PCa in the fourth decade with PSA between 2.6 and 4 ng/ml (12.5 times higher) and in the fifth decade with PSA between 4.1 and 10 ng/ml (6.2 times higher).

CONCLUSIONS

Age and serum PSA levels are the major risk factors for PCa. On their basis it is possible to modulate the most suitable timing for early diagnosis in individual patients.

Partial crystallization of an amorphous alloy by electronic energy deposition

The first experimental evidence is reported of crystallization induced in an amorphous alloy by a high density of electronic excitation deposited along the path of swift heavy ions. The formation of nanocrystalline iron boride phases was observed in an amorphous Fe73.5Cu1Nb3Si13.5B9 alloy irradiated at low temperature with 5 GeV Pb ions up to fluences of 1 x 10(11) ions cm-2. No evidence for the formation of the Fe(Si) phase was found. This phenomenon was interpreted in terms of the relaxation of the high level of energy deposited in electronic excitations along the path of Pb ions in the target, which induces extensive stress and strain that could destabilize the amorphous structure.

An uncommon case of cutaneous facial metastasis as the first manifestation of renal carcinoma

The authors report an unusual case of a 67-year-old man without urinary symptoms, with facial neoplasm. After biopsy, histological findings revealed a clear cell metastasis from renal carcinoma. Intravenous pyelography plus abdominal and brain CT scan were therefore performed, revealing renal cancer with widespread metastasis, making surgery impossible. Given the peculiarity of this case, the authors also give data from international literature which show that this type of first manifestation of renal carcinoma is very uncommon.

[Bladder hernia]

A case of bladder hernia in a 61 years old patient affected by benign prostatic hypertrophy is presented. Pre-operative diagnosis was made by cystography. After an adenomiomectomy of the prostate, the patient underwent the resection of the herniated bladder which gave the bladder its normal shape with only a slight reduction of its capacity. Inguino-scrotal bladder hernias are very rare; recognized predisponing factors are weakening of muscular and connective structures of the inguinal canal, and bladder hypotonia secondary to urethro-prostatic obstruction. These hernias, according to the anatomical position of the hernial sac, bladder and peritoneum, are classified in paraperitoneal (most frequent), intraperitoneal and extraperitoneal. The typical symptom of this disease is the two-stage micturition: the patient after a first spontaneous voiding, presses the mass and voids again. Other than cystography, useful diagnostic means are urography and cystoscopy which may confirm the diagnosis and rule out associated urinary disease. The treatment consists of either simple reduction of the bladder hernia, if the hernia is small, or resection of the herniated portion of the bladder, if the hernia is large or is associated with other diseases (e.g. tumors). Bladder resection is then followed by closure of the bladder wall in two layers and by inguinal hernia repair.

[Papilloma of the gallbladder]

Gall-bladder papilloma, although rare to be found, should be considered as a precancerous lesion, the sole treatment of which is the surgical one. The authors, starting from three cases of such pathology, they had the opportunity to observe, deal with histogenesis, symptomatology and treatment of such disease, and indicate the possibility for a careful diagnosis through the modern diagnostical means.

[Our experience with closed injuries of the pancreas]

The authors illustrate the types of anatomo-pathologic lesions, symptomatology, diagnostical means and treatment of pancreatic blunt trauma. They describe their experience about 4 cases (1,94%) of pancreatic trauma out of 210 abdominal blunt trauma. They, moreover, emphasize the usefulness of laparoscopy as an investigating mean offering a sure diagnostical reliability.

[Spontaneous hemoperitoneum]

The authors report their experience of 11 cases of hemoperitoneum due to hemorrhagic endoabdominal neoformation, diagnosed through laparoscopy, and the diagnosis of which was confirmed by the biopsy under the sight. They describe the casuistry observed: 4 hepatic neoplasms (11,9%); 4 ovary neoplasmus (12,1%); 1 neuroblastoma (10%); 2 ovary endometriosic cysts (16,6%). They, at last, emphasize the usefulness of laparoscopy as an investigating mean offering a sure diagnostical reliability.

[Closed injuries of the liver]

The authors shortly illustrate the etiopathogenesis, symptomatology, diagnosis, complications and treatment of liver blunt trauma. They describe their experience of 33 hepatic lesions out of 210 abdominal blunt trauma with a 12,1% mortality, and emphasize the usefulness of the laparoscopic investigation in the precocious diagnosis of such disease.

[Graduated and constant compression of the lower extremities in the prevention of postoperative deep venous thrombosis and of pulmonary thromboembolism. Clinical trial]

The authors report their experience with graded-pressure elastic hose (TED Stockings) for the prevention of deep venous thrombosis of the lower limbs and pulmonary embolism in high-risk, bedridden postoperative patients. The trial was designed according to a closed sequential program and gave positive, statistically significant results in terms of preventing pathology with this type of hose.