Producing lasting amphiphobic building surfaces with self-cleaning properties.

Nowadays, producing building surfaces that prevent water and oil uptake and which present self-cleaning activity is still a challenge. In this study, amphiphobic (superhydrophobic and oleophobic) building surfaces were successfully produced. A simple and low-cost process was developed, which is applicable to large-scale building surfaces, according the following procedure: (1) by spraying a SiO2 nanocomposite which produces a closely-packed nanoparticle uniform topography; (2) by functionalizing the previous coating with a fluorinated alkoxysilane, producing high hydrophobicity and oleophobicity. The formation of a Cassie-Baxter regime, in which air pockets could be trapped between the aggregates of particles, was confirmed by topographic study. The building surface demonstrated an excellent self-cleaning performance. Finally, the surface presented lasting superhydrophobicity with high stability against successive attachment/detachment force cycles. This high durability can be explained by the effective grafting of the silica nanocomposite coating skeleton with the substrate, and with the additional fluorinated coating produced by condensation reactions.

Producing superhydrophobic roof tiles.

Superhydrophobic materials can find promising applications in the field of building. However, their application has been very limited because the synthesis routes involve tedious processes, preventing large-scale application. A second drawback is related to their short-term life under outdoor conditions. A simple and low-cost synthesis route for producing superhydrophobic surfaces on building materials is developed and their effectiveness and their durability on clay roof tiles are evaluated. Specifically, an organic-inorganic hybrid gel containing silica nanoparticles is produced. The nanoparticles create a densely packed coating on the roof tile surface in which air is trapped. This roughness produces a Cassie-Baxter regime, promoting superhydrophobicity. A surfactant, n-octylamine, was also added to the starting sol to catalyze the sol-gel process and to coarsen the pore structure of the gel network, preventing cracking. The application of ultrasound obviates the need to use volatile organic compounds in the synthesis, thereby making a 'green' product. It was also demonstrated that a co-condensation process effective between the organic and inorganic species is crucial to obtain durable and effective coatings. After an aging test, high hydrophobicity was maintained and water absorption was completely prevented for the roof tile samples under study. However, a transition from a Cassie-Baxter to a Wenzel state regime was observed as a consequence of the increase in the distance between the roughness pitches produced by the aging of the coating.

A Simple, Long-Lasting Treatment for Concrete by Combining Hydrophobic Performance with a Photoinduced Superhydrophilic Surface for Easy Removal of Oil Pollutants.

Superhydrophobic surfaces present promising applications in the protection of building materials, such as the self-cleaning effect promoted by their high water-repellent properties. However, these surfaces easily lose their properties when exposed to oil contaminants. This is a critical weak point for their application in building facades, which are exposed to environmental pollutants such as hydrocarbons and vandalism (e.g., grafitti). A viable strategy to remove oils is to produce superhydrophilic surfaces, which present underwater superoleophobic behavior. In the case of buildings, the use of this strategy can be considered counterproductive because it promotes their interaction with water, the main vehicle of most decay agents. In this work, we have successfully combined the advantages of a superhydrophilic coating with a hydrophobic impregnation treatment, which prevents water ingress into the porous structure of the substrate. Specifically, a photoinduced superhydrophilic surface was produced on concrete by simple spraying of a starting sol containing TiO2NPs, which create a Cassie-Baxter state, a silica oligomer, producing a compatible matrix promoting good adhesion to the substrate and polydimethylsiloxane as a hydrophobic agent. After being exposed to sunlight, the treated surfaces switched from superhydrophobic (SCA 160°) to superhydrophilic (SCA < 10°). These surfaces presented underwater superoleophobicity (SCA 152° with CHCl3) and oil-contaminated dust was easily cleaned without employing detergents. The photoactivation does not alter the protection against water absorption (>85% reduction). The treatment showed suitable adhesion to the substrate and good resistance to rainfall and outdoor exposure due to the presence of the hydrophobic silica matrix in the concrete pore structure.

Long-term results of concomitant boost radiation plus concurrent cisplatin for advanced head and neck carcinomas: a phase II trial of the radiation therapy oncology group (RTOG 99-14).

PURPOSE: The feasibility of combining concomitant boost-accelerated radiation regimen (AFX-C) with cisplatin was previously demonstrated in this Phase II trial. This article reports the long-term toxicity, relapse patterns, and survival in patients with advanced head and neck carcinoma. METHODS AND MATERIALS: Between April and November 2000, 84 patients with Stage III-IV HNC were enrolled, and 76 patients were analyzable. Radiation consisted of 72 Gy over 6 weeks. Cisplatin dose was 100 mg/m(2) on Days 1 and 22. Tumor and clinical status were assessed, and acute-late toxicities were graded. RESULTS: The median follow-up for surviving patients is 4.3 years. The 2- and 4-year locoregional failure rates were 33% and 36%, respectively, and the 2- and 4-year survival rates were 70% and 54%, respectively. The worst overall late Grade 3 or 4 toxicity rate was 42%. The prevalence rates of a gastrostomy at any time during follow-up, at 12 months, and at 48 months were 83%, 41%, and 17%, respectively. Five of 36 patients (14%) alive and without disease at last follow-up were gastrostomy-tube dependent. CONCLUSION: These data of long-term follow-up of patients treated with AFX-C with cisplatin show encouraging results with regard to locoregional disease control and survival, with few recurrences after 2 years. The late toxicity rates are relatively high. However, although prolonged dysphagia was noted in our preliminary report, its prevalence does decreased over time. A Phase III trial comparing AFX-C plus cisplatin against standard radiation plus cisplatin has completed accrual.

Long-Term Effectiveness, under a Mountain Environment, of a Novel Conservation Nanomaterial Applied on Limestone from a Roman Archaeological Site.

A novel alkoxysilane-based product was applied on limestone samples from a Roman archaeological site. The study consisted of an initial phase to evaluate site environmental conditions in order to choose the most suitable product type to be applied. The decay that was produced in the site is mainly caused by natural action, with water being the main vehicle for the decay agents. Thus, the effectiveness of an innovative product with hydrophobic/consolidant properties and two commercial products (consolidant and hydrophobic agent) were evaluated on limestone from Acinipo site, under laboratory conditions. Next, the long-term effectiveness of the three products under study was evaluated by the exposure of limestone samples in the archaeological site for a period of three years. Since the recognized incompatibility between alkoxysilanes and pure carbonate stones, the interaction between the products and the limestones was widely investigated. The results that were obtained allow for it to be concluded that the innovative product presents adequate compatibility and adherence to the limestone under study, producing a long-term effective, homogeneous, and continuous coating with a depth of penetration of up to 10 mm. However, the commercial products produced discontinuous aggregates on the limestone surface, did not penetrate into its porous structure and it did not produce long-lasting effects.

Palliation of pelvic and head and neck cancer with paclitaxel and a novel radiotherapy regimen.

PURPOSE: In patients with advanced malignancies, local palliation is undertaken if the patient is not a candidate for aggressive intervention. We developed a prospective study using the same radiotherapy schedule as the Radiation Therapy Oncology Group (RTOG) 85-02 with the addition of the radiosensitizer paclitaxel to evaluate its effect on the tumor response rate, palliation of symptoms, and toxicity. METHODS: Twenty subjects with advanced pelvic or head and neck cancer were enrolled after signing an informed consent. Paclitaxel 60 mg/m(2) was administered 1 hour prior to the first day of each radiation cycle. Radiation therapy was delivered in 2 daily fractions of 3.7 Gy for 2 days every 3 weeks for three cycles (total dose 44.4 Gy). This radiotherapy schedule is referred to as "Quad Shot'' at our institution. RESULTS: Nineteen patients had adequate follow-up data and were considered evaluable. Five patients had a complete response (CR) and 13 patients had a partial response (PR) with symptomatic improvement for a response rate of 94.7%. One patient only had a minimal response. Seventeen patients (89.5%) had palliation of their presenting symptom(s). Eight patients had effective palliative benefit lasting more than 6 months. Two patients experienced a grade 2 allergic reaction to paclitaxel, one of them received the last cycle of treatment with cisplatin obtaining a CR. No late toxicities have been observed. CONCLUSIONS: This palliative schedule has been shown to provide good tumor response and palliation of symptoms. The toxicity profile remains low with the addition of paclitaxel. Further investigation is warranted in a larger trial. Palliation of symptoms resulted in improved quality of life for this group of patients.

Concomitant boost radiation plus concurrent cisplatin for advanced head and neck carcinomas: radiation therapy oncology group phase II trial 99-14.

PURPOSE: To investigate the feasibility of combining concomitant boost accelerated radiation regimen (AFX-C) with cisplatin and to assess its toxicity and the relapse pattern and survival in patients with advanced head and neck carcinoma (HNC). PATIENTS AND METHODS: Between April and November of 2000, 84 patients with stage III to IV HNC who met the eligibility criteria were enrolled; 76 of these patients were analyzable. Radiation consisted of 72 Gy in 42 fractions over 6 weeks (daily for 3.5 weeks, then twice a day for 2.5 weeks). Cisplatin dose was 100 mg/m(2) on days 1 and 22. Tumor and clinical status were assessed, and acute late toxicities were graded. RESULTS: Sixty-five patients (86%) received both radiation and chemotherapy per protocol or with minor variations. The estimated 2-year locoregional relapse and distant metastasis rates were 34.7% and 16.1%, respectively. The estimated 2-year overall survival and disease-free survival rates were 71.6% and 53.5%, respectively. Three patients (4%) died of complications, 19 patients (25%) had acute grade 4 toxicity, and 49 patients (64%) had acute grade 3 toxicity. The 2-year cumulative incidence of late grade 3 to 5 toxicities was 51.3%. CONCLUSION: These data showed that it was feasible to combine AFX-C with cisplatin. The compliance to therapy was high, and the locoregional control and survival rates achieved compared favorably with AFX-C alone or other concurrent chemoradiation regimens tested by the Radiation Therapy Oncology Group. A phase III trial comparing AFX-C plus cisplatin against standard radiation plus cisplatin is ongoing to determine whether the use of AFX-C in the concurrent chemoradiation setting further improves outcome.

Hodgkin's lymphoma in adults--clinical features.

One hundred (100) patients were treated in the Department of Radiation Oncology, James Graham Brown Cancer Center, University of Louisville School of Medicine, from 1980-1994. All patients were evaluated and staged according to the accepted guidelines at the treatment times. All patients were followed on a strict follow-up schedule for the outcome of treatment including late effects. The age range was 18 years-77 years. The age groupings are described in Table 1. Eighty-one percent (81%) of the patients were 40 years of age or younger. Nineteen percent (19%) of the patients were older and this was similar to the reported bimodal pattern in Hodgkin's disease. Fifty-eight percent (58%) of the patients were female and the rest were male. Eighty-eight percent (88%) of the patients were Caucasian as depicted in Table 2. Majority of the patients (64) presented with mass in the neck. Some of the patients presented with one or more symptoms and signs. The details of the presentation features are shown in Table 3. Thirty-one percent (31%) of the patients presented with one or more of the 'B' symptoms as described by Cotswolds Staging Classification for Hodgkin's Disease. These include fever (temperature >38 degrees C), drenching night sweats, and unexplained loss of >10% body weight within the preceding 6 months. Appropriate staging included complete physical examination, blood studies, and imaging studies such as plain chest x-rays, lymphangiograms, CT scans, gallium scans, etc. Forty-eight percent (48%) of the patients had staging laparotomy with lymph node sampling, splenectomy, and liver biopsies. The staging was done according to Ann Arbor Staging Classification. Forty-four percent (44%) of the patients were in Stage IIA group and the rest are shown in Table 4. Of the sites of involvement, neck (82 patients) and mediastinum (79 patients) were the common sites. Other sites of involvement are described in Table 5. Many patients had more than one site of involvement. Thirty-three percent (33%) of the patients had bulky mediastinal disease. This was defined based on the ratio of the width of the lesion to the transverse diameter of the chest. The most common histological subtype was nodular sclerosing (73%). This would explain the gender variation in this group of patients. The histological classification was done according to the Rye Classification (Table 6).

Evaluation of scrotal and testicular radiation doses for heterotopic ossification prophylaxis.

The majority of patients with heterotopic ossification are males with traumatic injuries in the hip/femur region. The testes, given their proximity, are exposed to scatter radiation, which has the potential to alter sperm count and morphology. In a prospective study, patients were treated with an 800-cGy dose of radiation without direct exposure of the testes/scrotum but with a testicular shield. Thermoluminescent dosimeters were placed inside and outside the shield. Mean dose inside and outside the shield was 10.2 and 20.2 cGy, respectively (sperm abnormalities have been reported with 15 cGy). Given our study results, young males should be counseled and should be treated with a testicular shield.

The relationship of radiation pneumonitis to treated lung volume in breast conservation therapy.

Breast conservation therapy has become a common modality for therapy of early stage breast cancer. Most studies of primary lung irradiation correlate the risk of pneumonitis with the volume of lung treated. It is proposed that the lung volume treated during tangential radiation of the intact breast may be calculated from a measurement of the central lung distance. Central lung distance is the distance from the chest wall to the edge of the field at the central axis. This study examines whether the incidence of radiation pneumonitis indeed correlates with the lung volume treated as calculated from a measurement of the central lung distance. From January 1, 1985, through December 31, 1998, 353 patients were treated with breast conservation therapy at the University of Louisville. The charts were reviewed for any evidence of clinically significant radiation pneumonitis. The treatment films were obtained and the central lung distance ascertained. Four cases of radiation pneumonitis were identified. Three of these occurred after tangential radiation and one occurred in a retreatment field after bone marrow transplant. The overall rate of radiation pneumonitis was 1.2%. A central lung distance of less than 3 cm was found in 78.3% of patients and 21.7% had a central lung distance of three or greater. There was no correlation between central lung distance and the risk of radiation pneumonitis. Breast conservation therapy is a well-tolerated modality for treatment of early stage breast cancer. The incidence of radiation pneumonitis is very low and is usually associated with other factors in addition to the tangential field lung volume.