Three direct electrical currents, 3mA, 5mA and 10mA were applied to the amputated hind limbs of tadpole larvae (stage number 58) of the Egyptian toad, Bufo regularis Reuss to study their effects on restoration of the regenerative ability after transection at the knee joint level. 5mA current was found to be the most enhancing one. The present results were compared with the results of earlier studies for the same stage. It is suggested that, electrical stimulation enhances limb regeneration and cartilage formation in hind limbs of a metamorphic stage (number 58) ) of Bufo regularis after transection at the knee joint level and that the strength of the electrical current needed to evoke the regenerative ability decreases along the proximodistal axis of the amputated limb.

The effect of insulin on limb regeneration of a metamorphic stage of the tadpoles of the Egyptian toad, Bufo regularis Reuss was studied by using a single dose of insulin (1 µl/individual) after amputation at the mid shank. Insulin was found to increase the regenerative power of the amputated limbs and enhance the formation of large amounts of cartilage. One case of the treated animals regenerated four toes, while four other cases restored part of the foot, which was not seen in the control group. The nature of the effect of insulin was discussed.

Dobutamine (DBT) is a sympathomimetic amine drug that was designed as an inotropic agent for use in con-gestive heart failure.Hence, there wasan impetus to developarapid andaccurate methodfor monitoring theconcentration of DBT within clinical samples. To address this critical need, a novel In2O3and functionalizedmulti-walledcarbonnanotubesnanocomposite(In2O3@FMWCNTs)wassuccessfullypreparedandappliedinanelectrochemical sensor to detect DBT. The resulting sensor displayed electrocatalytic toward the oxidation ofDBT,whichattributedtothesynergisticeffectofIn2O3andFMWCNTs.Electrochemicalimpedancespectroscopy(EIS)studiesrevealedthatthesmallerchargetransferresistancevalue(Rct)wasobservedatIn2O3@FMWCNTsmodified glassy carbon spherical (GCS) paste electrode (PE) as compared to that of In2O3NPs/GCSPE,FMWCNTs/GCSPEandGCSPE,whichauthenticatesitsgoodconductivity.Furthermore,thecalculatedvalueofstandardrateconstant(ks)forthemodifiedelectrodedemonstratesthefastelectrontransferbetweenDBTandthe electrode surface. The fabricated electrochemical sensor indicated high selectivity and sensitivity for DBTdetermination over the oxidation of uric acid and ascorbic acid. The limit of detection of DBT at In2O3@FMWCNTs/GCSPEwasfoundtobe1.42×10−10M.TheproposedsensoriseffectivelyusedforthedetectionofDBTinbiologicalfluids,clinicalpatient bloodandin injectiondosageform.

Dobutamine (DBT) is a sympathomimetic amine drug that was designed as an inotropic agent for use in con-gestive heart failure.Hence, there wasan impetus to developarapid andaccurate methodfor monitoring theconcentration of DBT within clinical samples. To address this critical need, a novel In2O3and functionalizedmulti-walledcarbonnanotubesnanocomposite(In2O3@FMWCNTs)wassuccessfullypreparedandappliedinanelectrochemical sensor to detect DBT. The resulting sensor displayed electrocatalytic toward the oxidation ofDBT,whichattributedtothesynergisticeffectofIn2O3andFMWCNTs.Electrochemicalimpedancespectroscopy(EIS)studiesrevealedthatthesmallerchargetransferresistancevalue(Rct)wasobservedatIn2O3@FMWCNTsmodified glassy carbon spherical (GCS) paste electrode (PE) as compared to that of In2O3NPs/GCSPE,FMWCNTs/GCSPEandGCSPE,whichauthenticatesitsgoodconductivity.Furthermore,thecalculatedvalueofstandardrateconstant(ks)forthemodifiedelectrodedemonstratesthefastelectrontransferbetweenDBTandthe electrode surface. The fabricated electrochemical sensor indicated high selectivity and sensitivity for DBTdetermination over the oxidation of uric acid and ascorbic acid. The limit of detection of DBT at In2O3@FMWCNTs/GCSPEwasfoundtobe1.42×10−10M.TheproposedsensoriseffectivelyusedforthedetectionofDBTinbiologicalfluids,clinicalpatient bloodandin injectiondosageform.

Detailed field, litho-, bio-stratigraphic and paleoenvironmental studies on the Maastrichtian-Paleocene successions exposed at El-Qasr, Abu Tartur, Gabal El-Aguz and Darb Gaga sections at Kharga-Dakhla region, Western Desert, Egypt are attempted. Three rock units are recognized; Dakhla, Kurkur and Tarawan formations. Eight calcareous nannofossil and ten planktonic foraminiferal zones are recorded and integrated to determine a precise age dating. Four benthonic foraminiferal biofacies (A, B, C and D) are reconstructed using the R-mode (species) hierarchical cluster analysis. These biofacies along with the relative abundance of the calcareous nannofossil species are used to interpret the paleoenvironmental conditions as well as the depositional settings prevailed during deposition of the studied successions. The integration of these data led to the identification of significant hiatuses which could be linked to two syn-sedimentary tectonic events Tectonic Event I and II). Tectonic Event I at the Cretaceous/Paleogene (K/Pg) boundary has a regional effect and led to expose the southern part of the
Tethys margin which is represented by the present study area. Throughout the Early Danian, the sedimentary basin could be divided into two sub-basins at El-Qasr and G. El-Aguz sections separated by two sub-marine paleohighs at Abu Tartur and Darb Gaga sections which represented the northern extensions of the southern shallow Garra El-Arbain Facies. The effect of Tectonic Event II initialized at Danian and continued throughout Thanetian. This event is restricted to the eastern part at Darb Gaga and G. El-Aguz sections forming an areal paleohigh at Darb Gaga and a sub-marine paleohigh at G. El-Aguz sections.

In this work, catalysts of pure FePO4 and mixed with (1–20 wt%) of B2O3, WO3 and ZrO2 were synthesized and examined for the selective dehydration of methanol into dimethyl ether (DME). The synthesized catalysts were extensively characterized by different techniques such as thermal analysis (thermogravimetry and differential thermal analysis), X-ray diffraction, Fourier transform infrared, BET-surface area and Mössbauer spectroscopy. The surface acidities are also measured and discussed in details. Our results revealed that loading with 1–10 wt% of the various additives resulted in a remarkable improvement in both SBET and total number of acid sites of the catalysts. The results of poisoning of acid sites with pyridine (PY) and dimethyl pyridine (DMPY) specified that the acidic sites are of Brønsted type, while PY-TPD indicated that almost all of acid sites over the surface of these catalysts are of weak and intermediate strength. Catalytic activity studies established that the FePO4 promoted with 10 wt% of B2O3 or WO3 or ZrO2 are the most active catalysts with complete conversions of methanol into DME at 375, 350, and 325 °C, respectively. The significant catalytic performance of these catalysts is correlated well with the enhancement observed in both SBET and total acidity. Finally, these catalysts also exhibit a long-term stability towards the dehydration of methanol into DME for a duration time of 160 h.

In this work, catalysts of pure FePO4 and mixed with (1–20 wt%) of B2O3, WO3 and ZrO2 were synthesized and examined for the selective dehydration of methanol into dimethyl ether (DME). The synthesized catalysts were extensively characterized by different techniques such as thermal analysis (thermogravimetry and differential thermal analysis), X-ray diffraction, Fourier transform infrared, BET-surface area and Mössbauer spectroscopy. The surface acidities are also measured and discussed in details. Our results revealed that loading with 1–10 wt% of the various additives resulted in a remarkable improvement in both SBET and total number of acid sites of the catalysts. The results of poisoning of acid sites with pyridine (PY) and dimethyl pyridine (DMPY) specified that the acidic sites are of Brønsted type, while PY-TPD indicated that almost all of acid sites over the surface of these catalysts are of weak and intermediate strength. Catalytic activity studies established that the FePO4 promoted with 10 wt% of B2O3 or WO3 or ZrO2 are the most active catalysts with complete conversions of methanol into DME at 375, 350, and 325 °C, respectively. The significant catalytic performance of these catalysts is correlated well with the enhancement observed in both SBET and total acidity. Finally, these catalysts also exhibit a long-term stability towards the dehydration of methanol into DME for a duration time of 160 h.

In this work, catalysts of pure FePO4 and mixed with (1–20 wt%) of B2O3, WO3 and ZrO2 were synthesized and examined for the selective dehydration of methanol into dimethyl ether (DME). The synthesized catalysts were extensively characterized by different techniques such as thermal analysis (thermogravimetry and differential thermal analysis), X-ray diffraction, Fourier transform infrared, BET-surface area and Mössbauer spectroscopy. The surface acidities are also measured and discussed in details. Our results revealed that loading with 1–10 wt% of the various additives resulted in a remarkable improvement in both SBET and total number of acid sites of the catalysts. The results of poisoning of acid sites with pyridine (PY) and dimethyl pyridine (DMPY) specified that the acidic sites are of Brønsted type, while PY-TPD indicated that almost all of acid sites over the surface of these catalysts are of weak and intermediate strength. Catalytic activity studies established that the FePO4 promoted with 10 wt% of B2O3 or WO3 or ZrO2 are the most active catalysts with complete conversions of methanol into DME at 375, 350, and 325 °C, respectively. The significant catalytic performance of these catalysts is correlated well with the enhancement observed in both SBET and total acidity. Finally, these catalysts also exhibit a long-term stability towards the dehydration of methanol into DME for a duration time of 160 h.

Methanol dehydration process to dimethyl ether (DME) has been considered as one of the main routes to produce clean fuel i.e. DME. Thus, efficient catalyst is highly required for selective production of DME. Herein, UiO-66 was used as a precursor for the synthesis of zirconium oxide sulfate embedded carbon (ZrOSO4@C). The synthesis method involves one-step carbonization of UiO-66 in the presence of sulfuric acid (10 wt.%). Materials characterization using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), Raman spectroscopy approve the formation of high crystalline phase of ZrOSO4@C. Nitrogen adsorption-desorption isotherms and high resolution transmission electron microscope (HR-TEM) confirm the mesopore structure of the materials. Acidity analysis using pyridine-temperature programmed desorption (TPD), isopropanol dehydration corroborate that ZrOSO4@C has weak and intermediate acidic sites making ZrOSO4@C effective catalyst for methanol dehydration to DME. The materials offered full conversion (100%) with excellent selectivity (100%) at a relatively low temperature (250 oC). The catalyst exhibited a long-term stability for 120 h. Based on these results, DME is produced efficiently in terms of conversion, selectivity, and long-term stability.

Methanol dehydration process to dimethyl ether (DME) has been considered as one of the main routes to produce clean fuel i.e. DME. Thus, efficient catalyst is highly required for selective production of DME. Herein, UiO-66 was used as a precursor for the synthesis of zirconium oxide sulfate embedded carbon (ZrOSO4@C). The synthesis method involves one-step carbonization of UiO-66 in the presence of sulfuric acid (10 wt.%). Materials characterization using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), Raman spectroscopy approve the formation of high crystalline phase of ZrOSO4@C. Nitrogen adsorption-desorption isotherms and high resolution transmission electron microscope (HR-TEM) confirm the mesopore structure of the materials. Acidity analysis using pyridine-temperature programmed desorption (TPD), isopropanol dehydration corroborate that ZrOSO4@C has weak and intermediate acidic sites making ZrOSO4@C effective catalyst for methanol dehydration to DME. The materials offered full conversion (100%) with excellent selectivity (100%) at a relatively low temperature (250 oC). The catalyst exhibited a long-term stability for 120 h. Based on these results, DME is produced efficiently in terms of conversion, selectivity, and long-term stability.