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The black mamba is one of the world's most venomous snakes—its bite can kill a human in just half an hour. But along with deadly neurotoxins, the black mamba's venom¹ has a special ingredient: a painkiller² as potent³ as morphine. So says a study in the journal Nature.

Researchers isolated⁴ proteins from mamba venom called mambalgins, and injected them into mice. Then they tested how long it took those mice to yank their paws out of water heated to a painful—but not damaging—115 degrees Fahrenheit⁵. Turns out mice treated with mambalgins could take the heat for just as long as mice dosed with morphine, indicating the two drugs had similar pain-relieving effects.

Morphine works by binding⁶ opioid receptors, but mambalgins target a completely different pain pathway. Which is a good thing. Because they don't slow down breathing like opiates. And the body doesn't build up tolerance⁷ to mambalgins as fast as it does to morphine—meaning mambalgins could keep the pain away for longer. The French company Theralpha is now developing a drug from the venom. Just don't call it snake oil.

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1 venom
n.毒液，恶毒，痛恨
参考例句：
The snake injects the venom immediately after biting its prey.毒蛇咬住猎物之后马上注入毒液。 In fact,some components of the venom may benefit human health.事实上，毒液的某些成分可能有益于人类健康。

2 painkiller
n.止痛药
参考例句：
I shall persuade him to take the painkiller.我将说服他把药吃下去。 The painkiller only provides him a short respite from his pain.止痛药仅仅让他在疼痛中有短暂的疏解。

3 potent
adj.强有力的，有权势的；有效力的
参考例句：
The medicine had a potent effect on your disease.这药物对你的病疗效很大。 We must account of his potent influence.我们必须考虑他的强有力的影响。

4 isolated
adj.与世隔绝的
参考例句：
His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。 Patients with the disease should be isolated. 这种病的患者应予以隔离。

5 Fahrenheit
n./adj.华氏温度；华氏温度计(的)
参考例句：
He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。 The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。

6 binding
有约束力的，有效的，应遵守的
参考例句：
The contract was not signed and has no binding force. 合同没有签署因而没有约束力。 Both sides have agreed that the arbitration will be binding. 双方都赞同仲裁具有约束力。

7 tolerance
n.宽容；容忍，忍受；耐药力；公差
参考例句：
Tolerance is one of his strengths.宽容是他的一个优点。 Human beings have limited tolerance of noise.人类对噪音的忍耐力有限。