Removal of lead by using Raschig rings manufactured with mixture of cement kiln dust, zeolite and bentonite

The present investigation is a follow-up of study on manufacturing Raschig ring for removal of lead from aqueous solution. The mixtures were formulated using cement kiln dust, zeolite, and bentonite, normally used as natural adsorbents in the industrial scale, according to mixture design algorithm and response surface method. The pastes were prepared by addition of 28.0wt.% de-ionized water, containing 0.1wt.% carboxymethyl cellulose, with mixed powders. The adsorbents were fabricated by extrusion of the pastes in Raschig ring form and calcination at 500°C after drying in oven. The effects of starting materials on the mechanical behavior of rings were studied from view point of mixture design algorithm to optimize the adsorbent composition. This method demonstrated to yield valuable information on the effects of used materials on mechanical characteristics. The study concluded that the strength, reliability and sorption capacity of ring can be simultaneously optimized by the addition of 47.5wt.% cement kiln dust, 32.5wt.% zeolite, and 20.0wt.% bentonite. In the next part of work, the sorption kinetics was investigated. The kinetic study indicated that the modified model can successfully correlate the sorption data. The equilibrium result showed the possibility of lead immobilization by fabricated rings.

Evidence for the use PET for radiation therapy planning in patients with cervical cancer: a systematic review

BACKGROUND AND OBJECTIVE

In recent years, the role of positron emission tomography (PET) in the staging and management of gynecological cancers has been increasing. The aim of this study was to systematically review the role of PET in radiotherapy planning and brachytherapy treatment optimization in patients with cervical cancer.

DESIGN AND SETTING

Systematic literature review.

METHODS

Systematic review of relevant literature addressing the utilization of PET and/or PET-computed tomography (CT) in external-beam radiotherapy planning and brachytherapy treatment optimization. We performed an extensive PubMed database search on 20 April 2011. Nineteen studies, including 759 patients, formed the basis of this systematic review.

RESULTS

PET/ PET-CT is the most sensitive imaging modality for detecting nodal metastases in patients with cervical cancer and has been shown to impact external-beam radiotherapy planning by modifying the treatment field and customizing the radiation dose. This particularly applies to detection of previously uncovered para-aortic and inguinal nodal metastases. Furthermore, PET/ PET-CT guided intensity-modulated radiation therapy (IMRT) allows delivery of higher doses of radiation to the primary tumor, if brachytherapy is unsuitable, and to grossly involved nodal disease while minimizing treatment-related toxicity. PET/ PET-CT based brachytherapy optimization allows improved tumor-volume dose distribution and detailed 3D dosimetric evaluation of risk organs. Sequential PET/ PET-CT imaging performed during the course of brachytherapy form the basis of “adaptive” brachytherapy in cervical cancer.

CONCLUSIONS

This review demonstrates the effectiveness of pretreatment PET/ PET-CT in cervical cancer patients treated by radiotherapy. Further prospective studies are required to define the group of patients who would benefit the most from this procedure.

The effect of organic loading rate on bio-hydrogen production from pre-treated rice straw waste via mesophilic up-flow anaerobic reactor

Effect of organic loading rate (OLR) on the continuous biological H(2) production from pretreated rice straw waste using a mesophilic up-flow anaerobic reactor (UAR) was investigated for 140 d. OLR was varied from 7.1 to 26 g COD/ld. H(2) yield was significantly increased from 95.5 to 117 mmol/d, when OLR was largely increased from 7.1 to 21.4 gCOD/ld, respectively. However, further increase in OLR up to 26 g COD/ld, showed a decreasing trend to 107.1 mmol/d. Likewise, H(2) production increased with OLR at the range of 7.1-21.4 g COD/ld, and reached the maximum H(2) production of 2.6l/d. However, the H(2) production started to decrease with the further increase of OLR, and dropped to 2.2l/d at OLR of 26 g COD/ld. The COD and carbohydrate removal efficiency were over 70% and 80% at OLRs of 7.1-21.4 g COD/ld, and decreased thereafter.

Two stage anaerobic baffled reactors for bio-hydrogen production from municipal food waste

A two-step anaerobic baffled reactor (ABR-1 and ABR-2) for H2 production from municipal food waste (MFW) was investigated at a temperature of 26 °C. In ABR-1, the average yield of H2 at an HRT of 26 h and OLR of 58 kg COD/m3 d was 250 ml H2/g VS removed. As unexpected; the H2 production in the ABR-2 was further increased up to 370 ml H2/gVS removed at a HRT of 26 h and OLR of 35 kg COD/m3 d. The total H2 yield in the two-step process was estimated to be 4.9 mol H2/mol hexose. The major part of H2 production in the ABR-1 was due to the conversion of COD(particulate) (36%). In the ABR-2 the H2 yield was mainly due to the conversion of COD in the soluble form (76%). Based on these results MFW could be ideal substrate for H2 production in a two-step ABR processes.

[Surgical treatment of breast lesions: preliminary results of the screening program of the Ariana area]

OBJECTIVE

To report clinical, radiological and histological characteristics of the infraclinical breast lesions patients recruited via the large scale mammography breast cancer screening of l'Ariana state in Tunisia.

MATERIALS AND METHODS

Retrospective study over a period of 2 years. The recruitment of patients made on the occasion of the program of breast cancer screening.

RESULTS

During this period, 22 patients in our unity had had a surgical excision after wire localization. Ten patients were recruited by means of systematic breast cancer screening. In these cases, the mammographic findings were classified B.I.R.A.D.S 4 in 7 cases and BIRADS type 5 in 3 cases. Definitive histology concluded to benign disease in 4 cases and malignancy 6 cases. This collaboration enables the diagnosis an invasive ductal carcinoma in three cases.

CONCLUSION

The surgical excision after wire localization for non palpable breast lesions allows diagnosis of high-risk benign lesions and low-stage breast cancer. It is a reliable technique which indications have to be based on clinical and radiological strict criteria. This procedure is at present, and in developed countries, widely outstripped with the stereotactic core needle biopsy.

[Lesions classified ACR3 with the breast cancer screening mammography program of the Ariana area: features and problems encountered]

OBJECTIVE

This retrospective work is related to ACR3 mammograms of the program "Feasibility of breast cancer screening by mammography in Ariana Governorate" in order to evaluate the efficiency and short-term quality control of these probably benign lesions.

MATERIALS AND METHODS

Mammograms classified ACR3 raised the indication of further examination, futher mammogram (profile, expanded or compression). The monitoring and control period are explained to the patient by the radiologist.

RESULTS

6.6% mammograms were classified as ACR 3 with 71.3% under the age of 50 years. Breast is very dense in 20.5% of cases, and transparent in 6% of cases. Further exams has been performed in 94. 5% of cases with a profile in 52% of cases, enlarged in 22.1%, compression in 24.9% and ultrasound in 82.5%. The surveillance protocol was insufficient for 126 women lost to the 1st control, 32 women lost for the 2nd control and 19 women were lost to the 3rd control. After two years monitoring, 219 women were reclassified as ACR2 with a negative test. In 2 patients, we found an invasive ductal carcinoma at 4 months control.

CONCLUSION

ACR 3 mammograms are the most important operator dependent category. The diagnosis of probably benign lesion dependant of the analysis of images and requires a great experience of the radiologist and a comprehensive complementary examination. In this study, this assessment was often heavy in relation to the frequency of dense breasts itself in connection with the young age of patients. In addition, for this particular category, the need of training is important and in terms of public health cost, the management of ACR3 mammograms increases difficulties and cost of screening.

[Radiological protocol of large scale mammographic screeening for breast cancer in Ariana area of Tunisia]

We present the radiological protocol of the breast cancer screening program of Ariana state in Tunisia. Specifications of this protocol are largely inspired from the french model adapted to the socioeconomic Tunisian conditions. We explain the guidelines of the mammograph specifications, quality insurance of all the process, mammography procedure, double reading, complementary views and ultrasound indications and final results management.