Nanotechnology for endorsing abiotic stresses: a review on the role of nanoparticles and nanocompositions

Environmental stresses, including the salt and heavy metals contaminated sites, signify a threat to sustainable crop production. The existence of these stresses has increased in recent years due to human-induced climate change. In view of this, several remediation strategies including nanotechnology have been studied to find more effective approaches for sustaining the environment. Nanoparticles, due to unique physiochemical properties; i.e. high mobility, reactivity, high surface area, and particle morphology, have shown a promising solution to promote sustainable agriculture. Crop plants easily take up nanoparticles, which can penetrate into the cells to play essential roles in growth and metabolic events. In addition, different iron- and carbon-based nanocompositions enhance the removal of metals from the contaminated sites and water; these nanoparticles activate the functional groups that potentially target specific molecules of the metal pollutants to obtain efficient remediation. This review article emphasises the recent advancement in the application of nanotechnology for the remediation of contaminated soils with metal pollutants and mitigating different abiotic stresses. Different implementation barriers are also discussed. Furthermore, we reported the opportunities and research directions to promote sustainable development based on the application of nanotechnology.

Water stress memory in wheat/maize intercropping regulated photosynthetic and antioxidative responses under rainfed conditions

Drought is a most prevalent environmental stress affecting the productivity of rainfed wheat and maize in the semiarid Loess Plateau of China. Sustainable agricultural practices such as intercropping are important for enhancing crop performance in terms of better physiological and biochemical characteristics under drought conditions. Enzymatic and non-enzymatic antioxidant enzyme activities are associated with improved abiotic tolerance in crop plants, however, its molecular mechanism remains obscure. A 2-year field study was conducted to evaluate the influence of intercropping treatment viz. wheat mono-crop (WMC), maize mono-crop (MMC), intercropping maize (IM) and wheat (IW) crops, and nitrogen (N) application rates viz. control and full-dose of N (basal application at 150 and 235 kg ha-1 for wheat and maize, respectively) on chlorophyll fluorescence, gas exchange traits, lipid peroxidation, antioxidative properties and expression patterns of six tolerance genes in both crops under rainfed conditions. As compared with their respective monocropping treatments, IW and IM increased the Fo/Fm by 18.35 and 14.33%, PS-11 efficiency by 7.90 and 13.44%, photosynthesis by 14.31 and 23.97%, C-capacity by 32.05 and 12.92%, and stomatal conductance by 41.40 and 89.95% under without- and with-N application, respectively. The reductions in instantaneous- and intrinsic-water use efficiency and MDA content in the range of 8.76-26.30% were recorded for IW and IM treatments compared with WMC and MMC, respectively. Compared with the WMC and MMC, IW and IM also triggered better antioxidant activities under both N rates. Moreover, we also noted that intercropping and N addition regulated the transcript levels of six genes encoding non-enzymatic antioxidants cycle enzymes. The better performance of intercropping treatments i.e., IW and IM were also associated with improved osmolytes accumulation under rainfed conditions. As compared with control, N addition significantly improved the chlorophyll fluorescence, gas exchange traits, lipid peroxidation, and antioxidant enzyme activities under all intercropping treatments. Our results increase our understanding of the physiological, biochemical, and molecular mechanisms of intercropping-induced water stress tolerance in wheat and maize crops.

Nitrogen application enhances yield, yield-attributes, and physiological characteristics of dryland wheat/maize under strip intercropping

Intercropping has been acknowledged as a sustainable practice for enhancing crop productivity and water use efficiency under rainfed conditions. However, the contribution of different planting rows towards crop physiology and yield is elusive. In addition, the influence of nitrogen (N) fertilization on the physiology, yield, and soil water storage of rainfed intercropping systems is poorly understood; therefore, the objective of this experiment was to study the contribution of different crop rows on the physiological, yield, and related traits of wheat/maize relay-strip intercropping (RSI) with and without N application. The treatments comprised of two factors viz. intercropping with three levels (sole wheat, sole maize, and RSI) and two N application rates, with and without N application. Results showed that RSI significantly improved the land use efficiency and grain yield of both crops under rainfed conditions. Intercropping with N application (+N treatment) resulted in the highest wheat grain yield with 70.37 and 52.78% increase as compared with monoculture and without N application in 2019 and 2020, respectively, where border rows contributed the maximum followed by second rows. The increase in grain yield was attributed to higher values of the number of ears per square meter (10-25.33% more in comparison to sole crop without N application) during both study years. The sole wheat crop without any N application recorded the least values for all yield-related parameters. Despite the absence of significant differences, the relative decrease in intercropped maize under both N treatments was over 9% compared to the sole maize crop, which was mainly ascribed to the border rows (24.65% decrease compared to the sole crop) that recorded 12 and 13% decrease in kernel number and thousand-grain weight, respectively than the sole crop. This might be attributed to the reduced photosynthesis and chlorophyll pigmentation in RSI maize crop during the blended growth period. In a nutshell, it can be concluded that wheat/maize RSI significantly improved the land use efficiency and the total yield compared to the sole crops' yield in arid areas in which yield advantages were mainly ascribed to the improvement in wheat yield.

Exogenous naphthaleneacetic acid alleviated alkalinity-induced morpho-physio-biochemical damages in Cyperus esculentus L. var. sativus Boeck

Cyperus esculentus L. var. sativus Boeck (commonly called Chufa) is a perennial species that produces nutritious underground tubers and contributes to the diet and health of human worldwide. However, it is salt-sensitive and its adaptation to salinity stress remains an enigma. Naphthaleneacetic acid (NAA) plays a vital role in regulating plant salt stress tolerance. Thus, we aimed to investigate the impact of NAA (150 mg/L) application on growth and physio-biochemical response mechanisms of Chufa plants to different levels of salinity stress (0-, 90-, and 180 mM of alkaline stress ([1:1 ratio of Na₂CO₃ and NaHCO₃]). In response to increasing stress levels, shoot-root growth decreased, whereas malondialdehyde (MDA), hydrogen peroxide (H₂O₂), osmolytes (soluble protein, proline, and soluble sugars), and activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) significantly increased. Alkalinity led to significant increase in Na⁺ and Cl^-, but decrease in Mg²⁺ concentration in both roots and leaves; however, K⁺ decreased significantly in leaves under both stresses. Additionally, NO 3 - and. levels, nitrate reductase (NR) activities, and glutamate synthase (GOGAT) decreased significantly. However, glutamine synthetase (GS) increased non-significantly at 90 mM but declined at 180 mM. Foliar NAA application reduced Na⁺ and Cl^-, MDA, and H₂O₂ but increased photosynthetic pigments, K⁺ and Mg²⁺, osmolytes, nitrogen (N) metabolism, and upregulating the enzymatic antioxidant system to reduce oxidative stress under alkaline conditions. Hence, our findings manifest that NAA application is an effective strategy that can be utilized to enhance tolerance of chufa plants to alkaline stress. Future studies should explore whether NAA can positively alter the nutrient composition of chufa tubers at deeper molecular levels, which might offer solutions to nutritious problems in developing countries.

Primary adenoid cystic carcinoma of the breast: Case report and review of the literature

Adenoid cystic carcinoma of the breast is a very rare neoplasm. We report a case of adenoid cystic carcinoma of the right breast presented with painless lump in the upper outer quadrant managed with lumpectomy, axillary lymph node staging and adjuvant local external radiotherapy to the whole breast with simultaneous integrated boost to the site of primary disease using respiratory gated intensity modulated radiotherapy. The available literature is reviewed.

KEYWORDS

Adenoid cystic cancer breast, mastectomy, adjuvant radiotherapy.

Acute respiratory distress syndrome in poor prognostic germ cell tumor with multiple lung metastases: a case report

We report a case which is unique as this patient was diagnosed pathologically as adenocarcinoma of the endometrium but clinically progressed as germ cell tumor. This was evident by progressive and rapid raised tumor markers (BHCG & LDH) with the development of multiple bilateral lung metastases. She was treated by administrating low doses of systemic combination chemotherapy as per the literature. Unfortunately, she developed acute respiratory distress syndrome as the complication of treatment and died due to it.

Respiratory gated simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) after breast conservative surgery for carcinoma of the breast: The Salmaniya Medical complex experience

PURPOSE

To present our clinical experience using SIB-IMRT Technique for Intact Breast cancer.

MATERIALS AND METHODS

A retrospective review of 45 cases of Stage I-IV breast cancer patients treated with SIB-IMRT with respiratory gating after Conservative treatments from 25th November 2008 to 16th February 2010. The most common fractionation was 1.8 Gy to Ipsilateral Breast tissue and 2.2 Gy to the lumpectomy cavity giving whole breast dose as 50.4 Gy and Lumpectomy cavity dose as 61.6 Gy over 28 fractions concomitantly. Respiratory gating was done and CT-images were taken in inspiratory breath hold position.

RESULTS

A total of 45 patients with breast cancer - stage I (17.7%), II (71%), III (8.9%), IV (2.2%) were treated with SIB- IMRT with respiratory gated radiotherapy. Out of 45 patients, 24 are of left sided breast cancer and 21 are of right sided breast cancer patients. The median, Dose maximum (D-max) in SIB-IMRT is 106.2% of prescribed lumpectomy site dose. The median isodose line prescribed to PTV-2 is 100%. The Conformity index (CI) is 0.9688 (median value) and Homogeneity index (HI) 1.06 (median). The median ipsilateral lung, mean dose is 21.66 Gy and V-20 is 37.4%. For left sided cases the median value of mean heart dose, V-30 and V-40 are 22.98 Gy, 23.45% and 9.45 % respectively. Acute skin toxicity was of Grade-I in 2.2 %, Grade-II in 64.4 %, Grade-III in 31.1 %, and Grade-IV in 2.2 %. The global Breast cosmoses were seen excellent in majority (93%) of case at median follow up of 8 months duration.

CONCLUSIONS

Breast SIB-IMRT Technique is feasible and comparable with other treatment techniques with reduced treatment duration by six fractions. At median follow up of 8 months the skin toxicity and cosmoses are excellent in high percentage of cases.

Ergoloids and ischaemic strokes; efficacy and mechanism of action

In this double-blind, randomized study the efficacy of the ergoloid compounds, co-dergocrine mesylate and nicergoline, in the rehabilitation of patients with ischaemic stroke was investigated. A group of 30 patients was treated daily with 60 mg nicergoline, orally, and a second group of 27 patients was given 1.8-6 mg co-dergocrine mesylate, orally or intramuscularly, daily (depending on the time since the initial ischaemic insult) for 6 months. Outcome measures included: motoricity index (limb function); Sandoz Clinical Assessment Geriatric (SCAG) scale; psychometric tests to assess functions such as attention, psychomotor performance, perception and sensory and short-term memory; conventional and computerized electroencephalography; and P300 and reaction time measures. The results showed improvements in some aspects such as limb function (P < 0.05), SCAG score (P < 0.01) and some electrophysiological parameters (P < 0.01) after treatment with both drugs. Though statistically significant most of the changes were not large. The efficacy of both drugs was qualitatively similar. The quantitative difference in some aspects in favour of nicergoline could be attributed to differences in the mechanisms of action of the two drugs, although it is also possible that the difference may reflect the dosages used. Nootropic drugs may induce a condition that facilitates the effects of cognitive training.