Coherently averaged dual-comb spectroscopy with a low-noise and high-power free-running gigahertz dual-comb laser: erratum.

This erratum corrects a typographical error in equation (8) of our published paper [Opt. Express31, 7103 (2023)10.1364/OE.479356]. All the calculations used the correct equation, so all the results and conclusions remain unchanged.

Coherently averaged dual-comb spectroscopy with a low-noise and high-power free-running gigahertz dual-comb laser.

We present a new type of dual optical frequency comb source capable of scaling applications to high measurement speeds while combining high average power, ultra-low noise operation, and a compact setup. Our approach is based on a diode-pumped solid-state laser cavity which includes an intracavity biprism operated at Brewster angle to generate two spatially-separated modes with highly correlated properties. The 15-cm-long cavity uses an Yb:CALGO crystal and a semiconductor saturable absorber mirror as an end mirror to generate more than 3 W average power per comb, below 80 fs pulse duration, a repetition rate of 1.03 GHz, and a continuously tunable repetition rate difference up to 27 kHz. We carefully investigate the coherence properties of the dual-comb by a series of heterodyne measurements, revealing several important features: (1) ultra-low jitter on the uncorrelated part of the timing noise; (2) the radio frequency comb lines of the interferograms are fully resolved in free-running operation; (3) we validate that through a simple measurement of the interferograms we can determine the fluctuations of the phase of all the radio frequency comb lines; (4) this phase information is used in a post-processing routine to perform coherently averaged dual-comb spectroscopy of acetylene (C2H2) over long timescales. Our results represent a powerful and general approach to dual-comb applications by combining low noise and high power operation directly from a highly compact laser oscillator.

Acute stress anticipates and amplifies the luteinizing hormone pre-ovulatory surge in rats: Role of noradrenergic neurons.

The stress experienced during rape seems to facilitate ovulation since the pregnancy rate in raped women is higher than that resulting from consensual intercourse. Adrenal progesterone, as well as central norepinephrine, is released in stressful situations. At adequate estrogenic levels, one of the main actions of progesterone is to anticipate the preovulatory LH surge through noradrenaline release. We aimed to investigate whether acute stresses that mimic those of rape (exposure to predator, restraint and cervix stimulation) applied on the proestrus morning in female rats could release progesterone, activate the noradrenergic neurons and facilitate the occurrence of the LH surge. Female rats were submitted to jugular vein cannulation immediately following acute stress: restraint (R), exposure to cat (P), uterine cervix stimulation (CS) applied individually or in association (SA). Non-stressed rats were used as control. Blood samples were collected from 11:00-18:00 h for LH, progesterone, corticosterone and estradiol measurements. Double labeling for c-Fos and tyrosine hydroxylase (TH) was examined in A1, A2 and A6 noradrenergic neurons after stresses. The SA group showed a greater stress-induced increase in progesterone compared to the other groups and the preovulatory LH surge was anticipated and amplified. This effect of SA seems to be related to the higher number of c-Fos/TH + neurons in the A1 and A2. The effect of anticipating the preovulatory surge of LH could in part elucidate why, in raped women, conception can occur in phases of the menstrual cycle other than the ovulatory phase facilitating the occurrence of pregnancies.

Uncertainty relation for the optimization of optical-fiber transmission systems simulations.

The mathematical inequality which in quantum mechanics gives rise to the uncertainty principle between two non commuting operators is used to develop a spatial step-size selection algorithm for the Split-Step Fourier Method (SSFM) for solving Generalized Non-Linear Schrödinger Equations (G-NLSEs). Numerical experiments are performed to analyze the efficiency of the method in modeling optical-fiber communications systems, showing its advantages relative to other algorithms.

Selective disruption of the E-cadherin-catenin system by an algal toxin.

Yessotoxins (YTXs) are algal toxins that can be accumulated in edible molluscs. YTX treatment of MCF-7 breast cancer cells causes the accumulation of a 100 kDa fragment of E-cadherin, which we have named ECRA(100). A relative decrease in the concentrations of intact E-cadherin did not accompany the accumulation of ECRA(100) in cytosoluble extracts of MCF-7 cells on the first day of YTX treatment, but a collapse of the E-cadherin system was detected after 2-5 days of treatment with the toxin. An analysis of the general structure of ECRA(100) revealed that it consists of an E-cadherin fragment lacking the intracellular domain of the protein. ECRA(100) was not released into culture media of YTX-treated cells. Accumulation of ECRA(100) was observed in other epithelial cells, such as human intestine Caco-2 and MDCK cells after treatment with YTX. In turn, YTX could not induce accumulation of fragments of other members of the cadherin family, such as N-cadherin in the PC12 cell line and K-cadherin in sensitive cells (MCF-7, Caco-2, MDCK). The accumulation of a 100 kDa fragment of E-cadherin devoid of its intracellular domain induced by YTX was accompanied by reduced levels of beta- and gamma-catenins bound to E-cadherin, without a concomitant decrease in the total cytosoluble pools of beta- and gamma-catenins. Taken together, the results we obtained show that YTX causes the selective disruption of the E-cadherin-catenin system in epithelial cells, and raise some concern about the potential that an algal toxin found in seafood might disrupt the tumour suppressive functions of E-cadherin.

Management of spontaneous bleeding due to hepatocellular carcinoma.

BACKGROUND: Spontaneous rupture is a life-threatening complication of HCC, occurring in 4.8-26% of cases. Liver failure is the main cause of death. Debates still remain on the most appropriate treatment in such patients because of the high operative mortality of emergency surgery and the high risk of rebleeding and less satisfying mid- and long-term results of nonoperative procedures like angiographic embolization. Early and long-term results of a surgically oriented treatment, based on prompt evaluation of the functional liver reserve and tumor resectability was retrospectively review-ed. METHODS: From January 1994 to December 2000, 11 patients (7 males and 4 female, mean age 66.2 (11.86 years) were treated for ruptured HCC, in 10 cases involving a cirrhotic liver. Seven patients underwent emergency surgery and 4 patients transcutaneous arterial embolization (TAE). Liver resection was performed in patients with preserved liver function, after ultrasonography and/or CT scan demonstrated hemoperitoneum and a single resectable liver tumour (5 cases). In one patient with cirrhosis, ultrasonography showed only hemoperitoneum. A bleeding nodule was discovered intraoperatively and resected in a liver with a multinodular HCC. Another patient under-went emergency resection after referral at our Unit with a surgical packing. In 4 cases with poor liver function and/or unresectable tumour TAE of the neoplasm was performed, in one case after surgical packing. Mortality, morbidity and patients survival after treatment were analyzed. All patients had at least 1 year follow-up. RESULTS: All patients underwent minor resection; 2 left lobectomies, 1 segmentectomy (VII), 1 bisegmentectomy (VII-VIII), and 3 wedge resections. Postoperative course was complicated by ascites in 5 cases and subphrenic abscess in one case. Four patients died 3, 4, 6 and 62 months after surgery; 3 patients are actually alive 22, 25, and 89 months after surgery. Four patients were submitted to TAE: all patients died within 6 months. CONCLUSIONS: When ruptured HCC is suspected, preserved liver function (Child A-B7) and a resectable hepatic tumour are considered clear indications to surgery. Emergency liver resection achieved good early and long-term results. In cases of advanced liver disease or multinodular HCC a non-operative approach, like TAE, must be attempted. Surgical direct hemostasis or hepatic artery ligation must be reserved for patients with uncontrollable o recurrent bleeding after TAE.

The use of laser-nephelometry in evaluating fibrinogenaemia in patients with hepatocarcinoma and cirrhosis.

In the present study fibrinogen was assayed by the immunonephelometric method in 19 patients afflicted with hepatocarcinoma and 24 patients afflicted with cirrhosis. The two groups were similar in age, sex and presence of HbsAg. The incidence of values above the norm was significantly greater in patients with hepatocarcinoma (p less than 0.05). Then, the concentration of fibrinogen was measured in all using two other immunological methods (Laurell and Mancini) and two coagulative methods (Clauss and Ratnoff). A dysfibrinogenemia (an excess of fibrinogen assayed by immunological methods to be greater than 100 mg/dl with respect to biological methods). is more frequent using the Nephelometer-Clauss (p less than 0.01) and Mancini-Clauss (p less than 0.01) methods in patients with hepatocarcinoma with respect to those with cirrhosis. The study of the kinetics of antifibrinogen antigen-antibody reaction failed to show differences between patients with hepatocarcinoma or cirrhosis and normal subjects.