1,538 research outputs found
Self-sustainable bio-methanol & bio-char coproduction from 2nd generation biomass gasification
Methanol is an important intermediate in the synthesis of different chemicals. It is mainly produced by reforming of natural gas in centralized facilities with productive capacities on the order of 109 tons per day. Production of methanol from biomass suffers from the cost and logistics of the transportation of biomass and it has not yet maturated into commercial scale. The techno-economic feasibility of the co-production of bio-methanol and bio-char is assessed through detailed computer simulations using process simulator Aspen HYSYS® together with the gasification simulator GASDS. This work further elaborates the previous results on the bio-methanol production process, presenting particularities and updates on previously reported values. The production model is seen to be valid, with payback times that go from 3 to 6 years according to the capacity of the plant (100 to 1000 kt of biomass per year). Self-sustainability is possible but a 50/50 mix of producing and buying electricity yields the most economic choice. © Copyright 2017, AIDIC Servizi S.r.l
Época e técnica de poda verde de pessegueiro 'charme' sobre a qualidade bioquimica dos frutos.
Parameterized Complexity of the k-anonymity Problem
The problem of publishing personal data without giving up privacy is becoming
increasingly important. An interesting formalization that has been recently
proposed is the -anonymity. This approach requires that the rows of a table
are partitioned in clusters of size at least and that all the rows in a
cluster become the same tuple, after the suppression of some entries. The
natural optimization problem, where the goal is to minimize the number of
suppressed entries, is known to be APX-hard even when the records values are
over a binary alphabet and , and when the records have length at most 8
and . In this paper we study how the complexity of the problem is
influenced by different parameters. In this paper we follow this direction of
research, first showing that the problem is W[1]-hard when parameterized by the
size of the solution (and the value ). Then we exhibit a fixed parameter
algorithm, when the problem is parameterized by the size of the alphabet and
the number of columns. Finally, we investigate the computational (and
approximation) complexity of the -anonymity problem, when restricting the
instance to records having length bounded by 3 and . We show that such a
restriction is APX-hard.Comment: 22 pages, 2 figure
Anabolic steroids purchased on the Internet as a cause of prolonged hypogonadotropic hypogonadism
OBJECTIVE: To report a case of hypogonadotropic hypogonadism due to the chronic abuse of anabolic steroids purchased over the Internet.
DESIGN: Case report.
SETTING: Endocrinology unit of the University of Brescia.
PATIENT(S): A 34-year-old man.
INTERVENTION(S): A single dose (100 μg) of triptorelin (triptorelin test).
MAIN OUTCOME MEASURE(S): Clinical symptoms, androgen normalization, levels of serum testosterone, follicle-stimulating hormone, and luteinizing hormone.
RESULT(S): Within 1 month, the patient's serum testosterone was in the normal range, and he reported a return to normal energy and libido.
CONCLUSION(S): The World Anti-Doping Code has proved to be a very powerful and effective tool in the harmonization of antidoping efforts worldwide, but it is insufficient to combat this illegal phenomenon. To tackle the serious side effects caused by doping we believe that it is necessary to increase monitoring and adopt severe sanctions, particularly with regard to Internet sites
On the canonical map of surfaces with q>=6
We carry out an analysis of the canonical system of a minimal complex surface
of general type with irregularity q>0. Using this analysis we are able to
sharpen in the case q>0 the well known Castelnuovo inequality K^2>=3p_g+q-7.
Then we turn to the study of surfaces with p_g=2q-3 and no fibration onto a
curve of genus >1. We prove that for q>=6 the canonical map is birational.
Combining this result with the analysis of the canonical system, we also prove
the inequality: K^2>=7\chi+2. This improves an earlier result of the first and
second author [M.Mendes Lopes and R.Pardini, On surfaces with p_g=2q-3, Adv. in
Geom. 10 (3) (2010), 549-555].Comment: Dedicated to Fabrizio Catanese on the occasion of his 60th birthday.
To appear in the special issue of Science of China Ser.A: Mathematics
dedicated to him. V2:some typos have been correcte
Modified percutaneous ethanol injection of parathyroid adenoma in primary hyperparathyroidism.
Surgery is the treatment of choice for symptomatic primary hyperparathyroidism; unlikely few patients do not meet established surgical criteria or have comorbid conditions that prohibit surgery. In these subjects, medical therapy alone offers little hope for a sustained long normocalcemic period. However percutaneous ethanol injection (PEI) may represent an alternative therapeutic procedure. It is currently in use for the treatment of secondary or tertiary hyperparathyroidism, however, few studies or case reports suggest it for the treatment of primary hyperparathyroidism. Moreover, little information is available about the long-term follow-up, where incomplete necrosis or the spreading of ethanol in the surrounding tissues is often reported. We believe that many of the side effects could be correlated to procedure itself. Taking these experiences into account, we have reasoned that in order to limit these side effects, we had to modify the standard PEI procedure. We reported this preliminary experience describing our modified PEI procedure
Prognostic value of thyrotropin receptor antibodies (TRAb) in Graves' disease: a 120 months prospective study
In most trials, at least 30-60% of patients with Graves' disease treated with antithyroid drugs relapse within 2 years after therapy withdrawal. At present, there are no prognostic parameters available early in treatment to indicate patients likely to achieve long-term remission. Because thyrotropin receptor autoantibodies (TRAb) are specific for Graves' disease, we evaluated the ability of their levels and of their rate of change to predict long-term prognosis. In our study 216 consecutive patients with newly diagnosed Graves' disease started a therapy with methimazole. Patients were treated until they achieved euthyroidism and TRAb were measured at 6-month intervals throughout a follow up of 120 months. Our study demonstrated that at the onset of hyperthyroidism patients' age, sex, fT4 levels and goiter size had no prognostic value in predicting long-term prognosis (respectively p = 0.79; p = 0.98; p = 0.83; p = 0.89). On the contrary, at the time of diagnosis TRAb titer was a good predictor of the final outcome (p<0.001); a titer equal to (or) more than 46.5 UI/L could identify patients who had never achieved long-term remission with a sensitivity of 52% and a specificity of 78%. Also fall rate of TRAb at 6 months of follow up and after therapy withdrawal were useful to predict the final outcome (p<0.001). At 6 months of follow up the time of therapy withdrawal, a decrease of TRAb lower than 52.3% or even its increase could identify patients who had never achieved permanent remission with a sensitivity of 55% and a specificity of 79.1%. No single parameter among TRAb, satisfactory identified a sub-set of patients who achieved long remission. Accordingly to our data, the best result in predicting long term remission is probably given by the presence of at least one of the two features evaluated at 6 months (TRAb titer and/or percentage of TRAb fall rate), with a sensitivity of 63% and specificity of 88%. TRAb titers evaluated both at the onset of hyperthyroidism that at 6 months of therapy or their rate of fall at 6 months and at ATD withdrawal are predictors of outcome. However, the presence of at least one, between titers of TRAb or their rate of fall at six months, resulted to be the best predictor of remission with the higher sensitivity and specificity
Management and therapeutic response of a prostate ductal adenocarcinoma: a still unknown tumour?
Ductal adenocarcinoma is a rare subtype of prostate cancer with a worse prognosis.Histologically, it is characterized by the presence of tall, pseudostratified columnar epithelium with abundant cytoplasm organized in a papillary or cribriform-papillary pattern. Several clinical differences distinguish this subtype of prostate cancer by the conventional acinar adenocarcinoma: exophytic growth into the prostatic urethra, different clinical presentation, different sites of metastasis and more aggressiveness. The rarity of this tumour forced to base our knowledge on small case series or on individual case reports, and does not help to establish appropriate guidelines. Therefore, the diagnosis of this tumour masks clinical implications that are still not well-understood.We report the case of a 69-year-old Caucasian man with a diagnosis of pure prostate ductal adenocarcinoma that early developed multiple metastases after radical prostatectomy. The patient started hormonal therapy with a fast biochemical and radiologic (positron emission tomography-computed tomography, PET-CT) hormonal escape. Therefore, we took the decision to perform chemotherapy with Taxotere along with prednisolone with a relative stability of prostate-specific antigen (PSA) level, but a new PET-CT scan showed a further progression of the disease. Finally, the patient underwent therapy with Abiraterone acetate that did not stop the cancer progression.No therapeutic options available showed a good control of disease progression. PSA proved to be a poor marker while, on the contrary, PET-CT scan has proved to be particularly useful in the management of the disease progression. More efforts are required to add new knowledge about this tumour and assess what is known until now
- …
