The non-linear relationships between the contents of ginsenoside Rg 1, Rb 1, Rd and Panax notoginseng saponins(PNS) in Panax notoginseng root herb and the near infrared(NIR) diffuse reflectance spectra of the herb wer...The non-linear relationships between the contents of ginsenoside Rg 1, Rb 1, Rd and Panax notoginseng saponins(PNS) in Panax notoginseng root herb and the near infrared(NIR) diffuse reflectance spectra of the herb were established by means of artificial neural networks(ANNs). Four three-layered perception feed-forward networks were trained with an error back-propagation algorithm. The significant principal components of the NIR spectral data matrix were utilized as the input of the networks. The networks architecture and parameters were selected so as to offer less prediction errors. Relative prediction errors for Rg 1, Rb 1, Rd and PNS obtained with the optimum ANN models were 8.99%, 6.54%, 8.29%, and 5.17%, respectively, which were superior to those obtained with PLSR methods. It is verified that ANN is a suitable approach to model this complex non-linearity. The developed method is fast, non-destructive and accurate and it provides a new efficient approach for determining the active components in the complex system of natural herbs.展开更多
Objective To evaluate the safety and efficacy of antegrade selective cerebral perfusion (ASCP) during aortic arch surgery as a means of extending the safe period of systemic circulatory arrest using multimodality neu...Objective To evaluate the safety and efficacy of antegrade selective cerebral perfusion (ASCP) during aortic arch surgery as a means of extending the safe period of systemic circulatory arrest using multimodality neuromonitoring to objectively quantify the physiologic responses Methods In twenty two patients (all less than age 60) scheduled for repair of an aortic arch aneurysm, preoperative verification of effective collateral perfusion through both the carotid and vertebrobasilar arterial systems was documented with transcranial Doppler ultrasonography (TCD) During cardiopulmonary bypass, the sole arterial inflow from the pump was via the right subclavian artery The magnitude of ASCP was quantified by TCD using peak middle cerebral artery velocity, while flow adequacy was measured by continuous regional cerebrovenous oxygen saturation (rSO 2) using dual wavelength spatially resolved near infrared spectroscopy Results All patients experienced an uneventful recovery Flow in the middle cerebral artery became undetectable at ASCP < 5?ml·kg 1 ·min 1 , so adjustments from a 15-20?ml·kg 1 ·min 1 baseline were used to maintain rSO 2 above 50% Furthermore, ASCP flow was highly correlated ( P <0 01) with both peak middle cerebral artery velocity and rSO 2 ( r =0 86 and 0 96, respectively) Conclusion Neuromonitoring guided ASCP may be expected to extend the safe period and is at least partly responsible for the absence of neurologic complications in this patient cohort展开更多
文摘The non-linear relationships between the contents of ginsenoside Rg 1, Rb 1, Rd and Panax notoginseng saponins(PNS) in Panax notoginseng root herb and the near infrared(NIR) diffuse reflectance spectra of the herb were established by means of artificial neural networks(ANNs). Four three-layered perception feed-forward networks were trained with an error back-propagation algorithm. The significant principal components of the NIR spectral data matrix were utilized as the input of the networks. The networks architecture and parameters were selected so as to offer less prediction errors. Relative prediction errors for Rg 1, Rb 1, Rd and PNS obtained with the optimum ANN models were 8.99%, 6.54%, 8.29%, and 5.17%, respectively, which were superior to those obtained with PLSR methods. It is verified that ANN is a suitable approach to model this complex non-linearity. The developed method is fast, non-destructive and accurate and it provides a new efficient approach for determining the active components in the complex system of natural herbs.
文摘Objective To evaluate the safety and efficacy of antegrade selective cerebral perfusion (ASCP) during aortic arch surgery as a means of extending the safe period of systemic circulatory arrest using multimodality neuromonitoring to objectively quantify the physiologic responses Methods In twenty two patients (all less than age 60) scheduled for repair of an aortic arch aneurysm, preoperative verification of effective collateral perfusion through both the carotid and vertebrobasilar arterial systems was documented with transcranial Doppler ultrasonography (TCD) During cardiopulmonary bypass, the sole arterial inflow from the pump was via the right subclavian artery The magnitude of ASCP was quantified by TCD using peak middle cerebral artery velocity, while flow adequacy was measured by continuous regional cerebrovenous oxygen saturation (rSO 2) using dual wavelength spatially resolved near infrared spectroscopy Results All patients experienced an uneventful recovery Flow in the middle cerebral artery became undetectable at ASCP < 5?ml·kg 1 ·min 1 , so adjustments from a 15-20?ml·kg 1 ·min 1 baseline were used to maintain rSO 2 above 50% Furthermore, ASCP flow was highly correlated ( P <0 01) with both peak middle cerebral artery velocity and rSO 2 ( r =0 86 and 0 96, respectively) Conclusion Neuromonitoring guided ASCP may be expected to extend the safe period and is at least partly responsible for the absence of neurologic complications in this patient cohort
